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deparse.c
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1/*-------------------------------------------------------------------------
2 *
3 * deparse.c
4 * Query deparser for postgres_fdw
5 *
6 * This file includes functions that examine query WHERE clauses to see
7 * whether they're safe to send to the remote server for execution, as
8 * well as functions to construct the query text to be sent. The latter
9 * functionality is annoyingly duplicative of ruleutils.c, but there are
10 * enough special considerations that it seems best to keep this separate.
11 * One saving grace is that we only need deparse logic for node types that
12 * we consider safe to send.
13 *
14 * We assume that the remote session's search_path is exactly "pg_catalog",
15 * and thus we need schema-qualify all and only names outside pg_catalog.
16 *
17 * We do not consider that it is ever safe to send COLLATE expressions to
18 * the remote server: it might not have the same collation names we do.
19 * (Later we might consider it safe to send COLLATE "C", but even that would
20 * fail on old remote servers.) An expression is considered safe to send
21 * only if all operator/function input collations used in it are traceable to
22 * Var(s) of the foreign table. That implies that if the remote server gets
23 * a different answer than we do, the foreign table's columns are not marked
24 * with collations that match the remote table's columns, which we can
25 * consider to be user error.
26 *
27 * Portions Copyright (c) 2012-2025, PostgreSQL Global Development Group
28 *
29 * IDENTIFICATION
30 * contrib/postgres_fdw/deparse.c
31 *
32 *-------------------------------------------------------------------------
33 */
34#include "postgres.h"
35
36#include "access/htup_details.h"
37#include "access/sysattr.h"
38#include "access/table.h"
40#include "catalog/pg_authid.h"
42#include "catalog/pg_database.h"
44#include "catalog/pg_operator.h"
45#include "catalog/pg_opfamily.h"
46#include "catalog/pg_proc.h"
48#include "catalog/pg_ts_dict.h"
49#include "catalog/pg_type.h"
50#include "commands/defrem.h"
51#include "nodes/nodeFuncs.h"
52#include "nodes/plannodes.h"
53#include "optimizer/optimizer.h"
54#include "optimizer/prep.h"
55#include "optimizer/tlist.h"
56#include "parser/parsetree.h"
57#include "postgres_fdw.h"
58#include "utils/builtins.h"
59#include "utils/lsyscache.h"
60#include "utils/rel.h"
61#include "utils/syscache.h"
62#include "utils/typcache.h"
63
64/*
65 * Global context for foreign_expr_walker's search of an expression tree.
66 */
67typedef struct foreign_glob_cxt
68{
69 PlannerInfo *root; /* global planner state */
70 RelOptInfo *foreignrel; /* the foreign relation we are planning for */
71 Relids relids; /* relids of base relations in the underlying
72 * scan */
74
75/*
76 * Local (per-tree-level) context for foreign_expr_walker's search.
77 * This is concerned with identifying collations used in the expression.
78 */
79typedef enum
80{
81 FDW_COLLATE_NONE, /* expression is of a noncollatable type, or
82 * it has default collation that is not
83 * traceable to a foreign Var */
84 FDW_COLLATE_SAFE, /* collation derives from a foreign Var */
85 FDW_COLLATE_UNSAFE, /* collation is non-default and derives from
86 * something other than a foreign Var */
88
89typedef struct foreign_loc_cxt
90{
91 Oid collation; /* OID of current collation, if any */
92 FDWCollateState state; /* state of current collation choice */
94
95/*
96 * Context for deparseExpr
97 */
98typedef struct deparse_expr_cxt
99{
100 PlannerInfo *root; /* global planner state */
101 RelOptInfo *foreignrel; /* the foreign relation we are planning for */
102 RelOptInfo *scanrel; /* the underlying scan relation. Same as
103 * foreignrel, when that represents a join or
104 * a base relation. */
105 StringInfo buf; /* output buffer to append to */
106 List **params_list; /* exprs that will become remote Params */
108
109#define REL_ALIAS_PREFIX "r"
110/* Handy macro to add relation name qualification */
111#define ADD_REL_QUALIFIER(buf, varno) \
112 appendStringInfo((buf), "%s%d.", REL_ALIAS_PREFIX, (varno))
113#define SUBQUERY_REL_ALIAS_PREFIX "s"
114#define SUBQUERY_COL_ALIAS_PREFIX "c"
115
116/*
117 * Functions to determine whether an expression can be evaluated safely on
118 * remote server.
119 */
120static bool foreign_expr_walker(Node *node,
121 foreign_glob_cxt *glob_cxt,
122 foreign_loc_cxt *outer_cxt,
123 foreign_loc_cxt *case_arg_cxt);
124static char *deparse_type_name(Oid type_oid, int32 typemod);
125
126/*
127 * Functions to construct string representation of a node tree.
128 */
130 RangeTblEntry *rte,
131 Index rtindex,
132 Relation rel,
133 bool is_returning,
134 Bitmapset *attrs_used,
135 bool qualify_col,
136 List **retrieved_attrs);
137static void deparseExplicitTargetList(List *tlist,
138 bool is_returning,
139 List **retrieved_attrs,
140 deparse_expr_cxt *context);
141static void deparseSubqueryTargetList(deparse_expr_cxt *context);
143 Index rtindex, Relation rel,
144 bool trig_after_row,
145 List *withCheckOptionList,
146 List *returningList,
147 List **retrieved_attrs);
148static void deparseColumnRef(StringInfo buf, int varno, int varattno,
149 RangeTblEntry *rte, bool qualify_col);
150static void deparseRelation(StringInfo buf, Relation rel);
151static void deparseExpr(Expr *node, deparse_expr_cxt *context);
152static void deparseVar(Var *node, deparse_expr_cxt *context);
153static void deparseConst(Const *node, deparse_expr_cxt *context, int showtype);
154static void deparseParam(Param *node, deparse_expr_cxt *context);
155static void deparseSubscriptingRef(SubscriptingRef *node, deparse_expr_cxt *context);
156static void deparseFuncExpr(FuncExpr *node, deparse_expr_cxt *context);
157static void deparseOpExpr(OpExpr *node, deparse_expr_cxt *context);
158static bool isPlainForeignVar(Expr *node, deparse_expr_cxt *context);
160static void deparseDistinctExpr(DistinctExpr *node, deparse_expr_cxt *context);
162 deparse_expr_cxt *context);
163static void deparseRelabelType(RelabelType *node, deparse_expr_cxt *context);
164static void deparseArrayCoerceExpr(ArrayCoerceExpr *node, deparse_expr_cxt *context);
165static void deparseBoolExpr(BoolExpr *node, deparse_expr_cxt *context);
166static void deparseNullTest(NullTest *node, deparse_expr_cxt *context);
167static void deparseCaseExpr(CaseExpr *node, deparse_expr_cxt *context);
168static void deparseArrayExpr(ArrayExpr *node, deparse_expr_cxt *context);
169static void printRemoteParam(int paramindex, Oid paramtype, int32 paramtypmod,
170 deparse_expr_cxt *context);
171static void printRemotePlaceholder(Oid paramtype, int32 paramtypmod,
172 deparse_expr_cxt *context);
173static void deparseSelectSql(List *tlist, bool is_subquery, List **retrieved_attrs,
174 deparse_expr_cxt *context);
175static void deparseLockingClause(deparse_expr_cxt *context);
176static void appendOrderByClause(List *pathkeys, bool has_final_sort,
177 deparse_expr_cxt *context);
178static void appendLimitClause(deparse_expr_cxt *context);
179static void appendConditions(List *exprs, deparse_expr_cxt *context);
181 RelOptInfo *foreignrel, bool use_alias,
182 Index ignore_rel, List **ignore_conds,
183 List **additional_conds,
184 List **params_list);
185static void appendWhereClause(List *exprs, List *additional_conds,
186 deparse_expr_cxt *context);
187static void deparseFromExpr(List *quals, deparse_expr_cxt *context);
189 RelOptInfo *foreignrel, bool make_subquery,
190 Index ignore_rel, List **ignore_conds,
191 List **additional_conds, List **params_list);
192static void deparseAggref(Aggref *node, deparse_expr_cxt *context);
193static void appendGroupByClause(List *tlist, deparse_expr_cxt *context);
194static void appendOrderBySuffix(Oid sortop, Oid sortcoltype, bool nulls_first,
195 deparse_expr_cxt *context);
196static void appendAggOrderBy(List *orderList, List *targetList,
197 deparse_expr_cxt *context);
198static void appendFunctionName(Oid funcid, deparse_expr_cxt *context);
199static Node *deparseSortGroupClause(Index ref, List *tlist, bool force_colno,
200 deparse_expr_cxt *context);
201
202/*
203 * Helper functions
204 */
205static bool is_subquery_var(Var *node, RelOptInfo *foreignrel,
206 int *relno, int *colno);
207static void get_relation_column_alias_ids(Var *node, RelOptInfo *foreignrel,
208 int *relno, int *colno);
209
210
211/*
212 * Examine each qual clause in input_conds, and classify them into two groups,
213 * which are returned as two lists:
214 * - remote_conds contains expressions that can be evaluated remotely
215 * - local_conds contains expressions that can't be evaluated remotely
216 */
217void
219 RelOptInfo *baserel,
220 List *input_conds,
221 List **remote_conds,
222 List **local_conds)
223{
224 ListCell *lc;
225
226 *remote_conds = NIL;
227 *local_conds = NIL;
228
229 foreach(lc, input_conds)
230 {
232
233 if (is_foreign_expr(root, baserel, ri->clause))
234 *remote_conds = lappend(*remote_conds, ri);
235 else
236 *local_conds = lappend(*local_conds, ri);
237 }
238}
239
240/*
241 * Returns true if given expr is safe to evaluate on the foreign server.
242 */
243bool
245 RelOptInfo *baserel,
246 Expr *expr)
247{
248 foreign_glob_cxt glob_cxt;
249 foreign_loc_cxt loc_cxt;
250 PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) (baserel->fdw_private);
251
252 /*
253 * Check that the expression consists of nodes that are safe to execute
254 * remotely.
255 */
256 glob_cxt.root = root;
257 glob_cxt.foreignrel = baserel;
258
259 /*
260 * For an upper relation, use relids from its underneath scan relation,
261 * because the upperrel's own relids currently aren't set to anything
262 * meaningful by the core code. For other relation, use their own relids.
263 */
264 if (IS_UPPER_REL(baserel))
265 glob_cxt.relids = fpinfo->outerrel->relids;
266 else
267 glob_cxt.relids = baserel->relids;
268 loc_cxt.collation = InvalidOid;
269 loc_cxt.state = FDW_COLLATE_NONE;
270 if (!foreign_expr_walker((Node *) expr, &glob_cxt, &loc_cxt, NULL))
271 return false;
272
273 /*
274 * If the expression has a valid collation that does not arise from a
275 * foreign var, the expression can not be sent over.
276 */
277 if (loc_cxt.state == FDW_COLLATE_UNSAFE)
278 return false;
279
280 /*
281 * An expression which includes any mutable functions can't be sent over
282 * because its result is not stable. For example, sending now() remote
283 * side could cause confusion from clock offsets. Future versions might
284 * be able to make this choice with more granularity. (We check this last
285 * because it requires a lot of expensive catalog lookups.)
286 */
287 if (contain_mutable_functions((Node *) expr))
288 return false;
289
290 /* OK to evaluate on the remote server */
291 return true;
292}
293
294/*
295 * Check if expression is safe to execute remotely, and return true if so.
296 *
297 * In addition, *outer_cxt is updated with collation information.
298 *
299 * case_arg_cxt is NULL if this subexpression is not inside a CASE-with-arg.
300 * Otherwise, it points to the collation info derived from the arg expression,
301 * which must be consulted by any CaseTestExpr.
302 *
303 * We must check that the expression contains only node types we can deparse,
304 * that all types/functions/operators are safe to send (they are "shippable"),
305 * and that all collations used in the expression derive from Vars of the
306 * foreign table. Because of the latter, the logic is pretty close to
307 * assign_collations_walker() in parse_collate.c, though we can assume here
308 * that the given expression is valid. Note function mutability is not
309 * currently considered here.
310 */
311static bool
313 foreign_glob_cxt *glob_cxt,
314 foreign_loc_cxt *outer_cxt,
315 foreign_loc_cxt *case_arg_cxt)
316{
317 bool check_type = true;
318 PgFdwRelationInfo *fpinfo;
319 foreign_loc_cxt inner_cxt;
320 Oid collation;
322
323 /* Need do nothing for empty subexpressions */
324 if (node == NULL)
325 return true;
326
327 /* May need server info from baserel's fdw_private struct */
328 fpinfo = (PgFdwRelationInfo *) (glob_cxt->foreignrel->fdw_private);
329
330 /* Set up inner_cxt for possible recursion to child nodes */
331 inner_cxt.collation = InvalidOid;
332 inner_cxt.state = FDW_COLLATE_NONE;
333
334 switch (nodeTag(node))
335 {
336 case T_Var:
337 {
338 Var *var = (Var *) node;
339
340 /*
341 * If the Var is from the foreign table, we consider its
342 * collation (if any) safe to use. If it is from another
343 * table, we treat its collation the same way as we would a
344 * Param's collation, ie it's not safe for it to have a
345 * non-default collation.
346 */
347 if (bms_is_member(var->varno, glob_cxt->relids) &&
348 var->varlevelsup == 0)
349 {
350 /* Var belongs to foreign table */
351
352 /*
353 * System columns other than ctid should not be sent to
354 * the remote, since we don't make any effort to ensure
355 * that local and remote values match (tableoid, in
356 * particular, almost certainly doesn't match).
357 */
358 if (var->varattno < 0 &&
360 return false;
361
362 /* Else check the collation */
363 collation = var->varcollid;
365 }
366 else
367 {
368 /* Var belongs to some other table */
369 collation = var->varcollid;
370 if (collation == InvalidOid ||
371 collation == DEFAULT_COLLATION_OID)
372 {
373 /*
374 * It's noncollatable, or it's safe to combine with a
375 * collatable foreign Var, so set state to NONE.
376 */
378 }
379 else
380 {
381 /*
382 * Do not fail right away, since the Var might appear
383 * in a collation-insensitive context.
384 */
386 }
387 }
388 }
389 break;
390 case T_Const:
391 {
392 Const *c = (Const *) node;
393
394 /*
395 * Constants of regproc and related types can't be shipped
396 * unless the referenced object is shippable. But NULL's ok.
397 * (See also the related code in dependency.c.)
398 */
399 if (!c->constisnull)
400 {
401 switch (c->consttype)
402 {
403 case REGPROCOID:
404 case REGPROCEDUREOID:
405 if (!is_shippable(DatumGetObjectId(c->constvalue),
406 ProcedureRelationId, fpinfo))
407 return false;
408 break;
409 case REGOPEROID:
410 case REGOPERATOROID:
411 if (!is_shippable(DatumGetObjectId(c->constvalue),
412 OperatorRelationId, fpinfo))
413 return false;
414 break;
415 case REGCLASSOID:
416 if (!is_shippable(DatumGetObjectId(c->constvalue),
417 RelationRelationId, fpinfo))
418 return false;
419 break;
420 case REGTYPEOID:
421 if (!is_shippable(DatumGetObjectId(c->constvalue),
422 TypeRelationId, fpinfo))
423 return false;
424 break;
425 case REGCOLLATIONOID:
426 if (!is_shippable(DatumGetObjectId(c->constvalue),
427 CollationRelationId, fpinfo))
428 return false;
429 break;
430 case REGCONFIGOID:
431
432 /*
433 * For text search objects only, we weaken the
434 * normal shippability criterion to allow all OIDs
435 * below FirstNormalObjectId. Without this, none
436 * of the initdb-installed TS configurations would
437 * be shippable, which would be quite annoying.
438 */
439 if (DatumGetObjectId(c->constvalue) >= FirstNormalObjectId &&
440 !is_shippable(DatumGetObjectId(c->constvalue),
441 TSConfigRelationId, fpinfo))
442 return false;
443 break;
444 case REGDICTIONARYOID:
445 if (DatumGetObjectId(c->constvalue) >= FirstNormalObjectId &&
446 !is_shippable(DatumGetObjectId(c->constvalue),
447 TSDictionaryRelationId, fpinfo))
448 return false;
449 break;
450 case REGNAMESPACEOID:
451 if (!is_shippable(DatumGetObjectId(c->constvalue),
452 NamespaceRelationId, fpinfo))
453 return false;
454 break;
455 case REGROLEOID:
456 if (!is_shippable(DatumGetObjectId(c->constvalue),
457 AuthIdRelationId, fpinfo))
458 return false;
459 break;
460 case REGDATABASEOID:
461 if (!is_shippable(DatumGetObjectId(c->constvalue),
462 DatabaseRelationId, fpinfo))
463 return false;
464 break;
465 }
466 }
467
468 /*
469 * If the constant has nondefault collation, either it's of a
470 * non-builtin type, or it reflects folding of a CollateExpr.
471 * It's unsafe to send to the remote unless it's used in a
472 * non-collation-sensitive context.
473 */
474 collation = c->constcollid;
475 if (collation == InvalidOid ||
476 collation == DEFAULT_COLLATION_OID)
478 else
480 }
481 break;
482 case T_Param:
483 {
484 Param *p = (Param *) node;
485
486 /*
487 * If it's a MULTIEXPR Param, punt. We can't tell from here
488 * whether the referenced sublink/subplan contains any remote
489 * Vars; if it does, handling that is too complicated to
490 * consider supporting at present. Fortunately, MULTIEXPR
491 * Params are not reduced to plain PARAM_EXEC until the end of
492 * planning, so we can easily detect this case. (Normal
493 * PARAM_EXEC Params are safe to ship because their values
494 * come from somewhere else in the plan tree; but a MULTIEXPR
495 * references a sub-select elsewhere in the same targetlist,
496 * so we'd be on the hook to evaluate it somehow if we wanted
497 * to handle such cases as direct foreign updates.)
498 */
499 if (p->paramkind == PARAM_MULTIEXPR)
500 return false;
501
502 /*
503 * Collation rule is same as for Consts and non-foreign Vars.
504 */
505 collation = p->paramcollid;
506 if (collation == InvalidOid ||
507 collation == DEFAULT_COLLATION_OID)
509 else
511 }
512 break;
513 case T_SubscriptingRef:
514 {
515 SubscriptingRef *sr = (SubscriptingRef *) node;
516
517 /* Assignment should not be in restrictions. */
518 if (sr->refassgnexpr != NULL)
519 return false;
520
521 /*
522 * Recurse into the remaining subexpressions. The container
523 * subscripts will not affect collation of the SubscriptingRef
524 * result, so do those first and reset inner_cxt afterwards.
525 */
527 glob_cxt, &inner_cxt, case_arg_cxt))
528 return false;
529 inner_cxt.collation = InvalidOid;
530 inner_cxt.state = FDW_COLLATE_NONE;
532 glob_cxt, &inner_cxt, case_arg_cxt))
533 return false;
534 inner_cxt.collation = InvalidOid;
535 inner_cxt.state = FDW_COLLATE_NONE;
536 if (!foreign_expr_walker((Node *) sr->refexpr,
537 glob_cxt, &inner_cxt, case_arg_cxt))
538 return false;
539
540 /*
541 * Container subscripting typically yields same collation as
542 * refexpr's, but in case it doesn't, use same logic as for
543 * function nodes.
544 */
545 collation = sr->refcollid;
546 if (collation == InvalidOid)
548 else if (inner_cxt.state == FDW_COLLATE_SAFE &&
549 collation == inner_cxt.collation)
551 else if (collation == DEFAULT_COLLATION_OID)
553 else
555 }
556 break;
557 case T_FuncExpr:
558 {
559 FuncExpr *fe = (FuncExpr *) node;
560
561 /*
562 * If function used by the expression is not shippable, it
563 * can't be sent to remote because it might have incompatible
564 * semantics on remote side.
565 */
566 if (!is_shippable(fe->funcid, ProcedureRelationId, fpinfo))
567 return false;
568
569 /*
570 * Recurse to input subexpressions.
571 */
572 if (!foreign_expr_walker((Node *) fe->args,
573 glob_cxt, &inner_cxt, case_arg_cxt))
574 return false;
575
576 /*
577 * If function's input collation is not derived from a foreign
578 * Var, it can't be sent to remote.
579 */
580 if (fe->inputcollid == InvalidOid)
581 /* OK, inputs are all noncollatable */ ;
582 else if (inner_cxt.state != FDW_COLLATE_SAFE ||
583 fe->inputcollid != inner_cxt.collation)
584 return false;
585
586 /*
587 * Detect whether node is introducing a collation not derived
588 * from a foreign Var. (If so, we just mark it unsafe for now
589 * rather than immediately returning false, since the parent
590 * node might not care.)
591 */
592 collation = fe->funccollid;
593 if (collation == InvalidOid)
595 else if (inner_cxt.state == FDW_COLLATE_SAFE &&
596 collation == inner_cxt.collation)
598 else if (collation == DEFAULT_COLLATION_OID)
600 else
602 }
603 break;
604 case T_OpExpr:
605 case T_DistinctExpr: /* struct-equivalent to OpExpr */
606 {
607 OpExpr *oe = (OpExpr *) node;
608
609 /*
610 * Similarly, only shippable operators can be sent to remote.
611 * (If the operator is shippable, we assume its underlying
612 * function is too.)
613 */
614 if (!is_shippable(oe->opno, OperatorRelationId, fpinfo))
615 return false;
616
617 /*
618 * Recurse to input subexpressions.
619 */
620 if (!foreign_expr_walker((Node *) oe->args,
621 glob_cxt, &inner_cxt, case_arg_cxt))
622 return false;
623
624 /*
625 * If operator's input collation is not derived from a foreign
626 * Var, it can't be sent to remote.
627 */
628 if (oe->inputcollid == InvalidOid)
629 /* OK, inputs are all noncollatable */ ;
630 else if (inner_cxt.state != FDW_COLLATE_SAFE ||
631 oe->inputcollid != inner_cxt.collation)
632 return false;
633
634 /* Result-collation handling is same as for functions */
635 collation = oe->opcollid;
636 if (collation == InvalidOid)
638 else if (inner_cxt.state == FDW_COLLATE_SAFE &&
639 collation == inner_cxt.collation)
641 else if (collation == DEFAULT_COLLATION_OID)
643 else
645 }
646 break;
647 case T_ScalarArrayOpExpr:
648 {
650
651 /*
652 * Again, only shippable operators can be sent to remote.
653 */
654 if (!is_shippable(oe->opno, OperatorRelationId, fpinfo))
655 return false;
656
657 /*
658 * Recurse to input subexpressions.
659 */
660 if (!foreign_expr_walker((Node *) oe->args,
661 glob_cxt, &inner_cxt, case_arg_cxt))
662 return false;
663
664 /*
665 * If operator's input collation is not derived from a foreign
666 * Var, it can't be sent to remote.
667 */
668 if (oe->inputcollid == InvalidOid)
669 /* OK, inputs are all noncollatable */ ;
670 else if (inner_cxt.state != FDW_COLLATE_SAFE ||
671 oe->inputcollid != inner_cxt.collation)
672 return false;
673
674 /* Output is always boolean and so noncollatable. */
675 collation = InvalidOid;
677 }
678 break;
679 case T_RelabelType:
680 {
681 RelabelType *r = (RelabelType *) node;
682
683 /*
684 * Recurse to input subexpression.
685 */
686 if (!foreign_expr_walker((Node *) r->arg,
687 glob_cxt, &inner_cxt, case_arg_cxt))
688 return false;
689
690 /*
691 * RelabelType must not introduce a collation not derived from
692 * an input foreign Var (same logic as for a real function).
693 */
694 collation = r->resultcollid;
695 if (collation == InvalidOid)
697 else if (inner_cxt.state == FDW_COLLATE_SAFE &&
698 collation == inner_cxt.collation)
700 else if (collation == DEFAULT_COLLATION_OID)
702 else
704 }
705 break;
706 case T_ArrayCoerceExpr:
707 {
709
710 /*
711 * Recurse to input subexpression.
712 */
713 if (!foreign_expr_walker((Node *) e->arg,
714 glob_cxt, &inner_cxt, case_arg_cxt))
715 return false;
716
717 /*
718 * T_ArrayCoerceExpr must not introduce a collation not
719 * derived from an input foreign Var (same logic as for a
720 * function).
721 */
722 collation = e->resultcollid;
723 if (collation == InvalidOid)
725 else if (inner_cxt.state == FDW_COLLATE_SAFE &&
726 collation == inner_cxt.collation)
728 else if (collation == DEFAULT_COLLATION_OID)
730 else
732 }
733 break;
734 case T_BoolExpr:
735 {
736 BoolExpr *b = (BoolExpr *) node;
737
738 /*
739 * Recurse to input subexpressions.
740 */
741 if (!foreign_expr_walker((Node *) b->args,
742 glob_cxt, &inner_cxt, case_arg_cxt))
743 return false;
744
745 /* Output is always boolean and so noncollatable. */
746 collation = InvalidOid;
748 }
749 break;
750 case T_NullTest:
751 {
752 NullTest *nt = (NullTest *) node;
753
754 /*
755 * Recurse to input subexpressions.
756 */
757 if (!foreign_expr_walker((Node *) nt->arg,
758 glob_cxt, &inner_cxt, case_arg_cxt))
759 return false;
760
761 /* Output is always boolean and so noncollatable. */
762 collation = InvalidOid;
764 }
765 break;
766 case T_CaseExpr:
767 {
768 CaseExpr *ce = (CaseExpr *) node;
769 foreign_loc_cxt arg_cxt;
770 foreign_loc_cxt tmp_cxt;
771 ListCell *lc;
772
773 /*
774 * Recurse to CASE's arg expression, if any. Its collation
775 * has to be saved aside for use while examining CaseTestExprs
776 * within the WHEN expressions.
777 */
778 arg_cxt.collation = InvalidOid;
779 arg_cxt.state = FDW_COLLATE_NONE;
780 if (ce->arg)
781 {
782 if (!foreign_expr_walker((Node *) ce->arg,
783 glob_cxt, &arg_cxt, case_arg_cxt))
784 return false;
785 }
786
787 /* Examine the CaseWhen subexpressions. */
788 foreach(lc, ce->args)
789 {
790 CaseWhen *cw = lfirst_node(CaseWhen, lc);
791
792 if (ce->arg)
793 {
794 /*
795 * In a CASE-with-arg, the parser should have produced
796 * WHEN clauses of the form "CaseTestExpr = RHS",
797 * possibly with an implicit coercion inserted above
798 * the CaseTestExpr. However in an expression that's
799 * been through the optimizer, the WHEN clause could
800 * be almost anything (since the equality operator
801 * could have been expanded into an inline function).
802 * In such cases forbid pushdown, because
803 * deparseCaseExpr can't handle it.
804 */
805 Node *whenExpr = (Node *) cw->expr;
806 List *opArgs;
807
808 if (!IsA(whenExpr, OpExpr))
809 return false;
810
811 opArgs = ((OpExpr *) whenExpr)->args;
812 if (list_length(opArgs) != 2 ||
815 return false;
816 }
817
818 /*
819 * Recurse to WHEN expression, passing down the arg info.
820 * Its collation doesn't affect the result (really, it
821 * should be boolean and thus not have a collation).
822 */
823 tmp_cxt.collation = InvalidOid;
824 tmp_cxt.state = FDW_COLLATE_NONE;
825 if (!foreign_expr_walker((Node *) cw->expr,
826 glob_cxt, &tmp_cxt, &arg_cxt))
827 return false;
828
829 /* Recurse to THEN expression. */
830 if (!foreign_expr_walker((Node *) cw->result,
831 glob_cxt, &inner_cxt, case_arg_cxt))
832 return false;
833 }
834
835 /* Recurse to ELSE expression. */
837 glob_cxt, &inner_cxt, case_arg_cxt))
838 return false;
839
840 /*
841 * Detect whether node is introducing a collation not derived
842 * from a foreign Var. (If so, we just mark it unsafe for now
843 * rather than immediately returning false, since the parent
844 * node might not care.) This is the same as for function
845 * nodes, except that the input collation is derived from only
846 * the THEN and ELSE subexpressions.
847 */
848 collation = ce->casecollid;
849 if (collation == InvalidOid)
851 else if (inner_cxt.state == FDW_COLLATE_SAFE &&
852 collation == inner_cxt.collation)
854 else if (collation == DEFAULT_COLLATION_OID)
856 else
858 }
859 break;
860 case T_CaseTestExpr:
861 {
862 CaseTestExpr *c = (CaseTestExpr *) node;
863
864 /* Punt if we seem not to be inside a CASE arg WHEN. */
865 if (!case_arg_cxt)
866 return false;
867
868 /*
869 * Otherwise, any nondefault collation attached to the
870 * CaseTestExpr node must be derived from foreign Var(s) in
871 * the CASE arg.
872 */
873 collation = c->collation;
874 if (collation == InvalidOid)
876 else if (case_arg_cxt->state == FDW_COLLATE_SAFE &&
877 collation == case_arg_cxt->collation)
879 else if (collation == DEFAULT_COLLATION_OID)
881 else
883 }
884 break;
885 case T_ArrayExpr:
886 {
887 ArrayExpr *a = (ArrayExpr *) node;
888
889 /*
890 * Recurse to input subexpressions.
891 */
892 if (!foreign_expr_walker((Node *) a->elements,
893 glob_cxt, &inner_cxt, case_arg_cxt))
894 return false;
895
896 /*
897 * ArrayExpr must not introduce a collation not derived from
898 * an input foreign Var (same logic as for a function).
899 */
900 collation = a->array_collid;
901 if (collation == InvalidOid)
903 else if (inner_cxt.state == FDW_COLLATE_SAFE &&
904 collation == inner_cxt.collation)
906 else if (collation == DEFAULT_COLLATION_OID)
908 else
910 }
911 break;
912 case T_List:
913 {
914 List *l = (List *) node;
915 ListCell *lc;
916
917 /*
918 * Recurse to component subexpressions.
919 */
920 foreach(lc, l)
921 {
922 if (!foreign_expr_walker((Node *) lfirst(lc),
923 glob_cxt, &inner_cxt, case_arg_cxt))
924 return false;
925 }
926
927 /*
928 * When processing a list, collation state just bubbles up
929 * from the list elements.
930 */
931 collation = inner_cxt.collation;
932 state = inner_cxt.state;
933
934 /* Don't apply exprType() to the list. */
935 check_type = false;
936 }
937 break;
938 case T_Aggref:
939 {
940 Aggref *agg = (Aggref *) node;
941 ListCell *lc;
942
943 /* Not safe to pushdown when not in grouping context */
944 if (!IS_UPPER_REL(glob_cxt->foreignrel))
945 return false;
946
947 /* Only non-split aggregates are pushable. */
948 if (agg->aggsplit != AGGSPLIT_SIMPLE)
949 return false;
950
951 /* As usual, it must be shippable. */
952 if (!is_shippable(agg->aggfnoid, ProcedureRelationId, fpinfo))
953 return false;
954
955 /*
956 * Recurse to input args. aggdirectargs, aggorder and
957 * aggdistinct are all present in args, so no need to check
958 * their shippability explicitly.
959 */
960 foreach(lc, agg->args)
961 {
962 Node *n = (Node *) lfirst(lc);
963
964 /* If TargetEntry, extract the expression from it */
965 if (IsA(n, TargetEntry))
966 {
967 TargetEntry *tle = (TargetEntry *) n;
968
969 n = (Node *) tle->expr;
970 }
971
972 if (!foreign_expr_walker(n,
973 glob_cxt, &inner_cxt, case_arg_cxt))
974 return false;
975 }
976
977 /*
978 * For aggorder elements, check whether the sort operator, if
979 * specified, is shippable or not.
980 */
981 if (agg->aggorder)
982 {
983 foreach(lc, agg->aggorder)
984 {
986 Oid sortcoltype;
987 TypeCacheEntry *typentry;
988 TargetEntry *tle;
989
991 agg->args);
992 sortcoltype = exprType((Node *) tle->expr);
993 typentry = lookup_type_cache(sortcoltype,
995 /* Check shippability of non-default sort operator. */
996 if (srt->sortop != typentry->lt_opr &&
997 srt->sortop != typentry->gt_opr &&
998 !is_shippable(srt->sortop, OperatorRelationId,
999 fpinfo))
1000 return false;
1001 }
1002 }
1003
1004 /* Check aggregate filter */
1005 if (!foreign_expr_walker((Node *) agg->aggfilter,
1006 glob_cxt, &inner_cxt, case_arg_cxt))
1007 return false;
1008
1009 /*
1010 * If aggregate's input collation is not derived from a
1011 * foreign Var, it can't be sent to remote.
1012 */
1013 if (agg->inputcollid == InvalidOid)
1014 /* OK, inputs are all noncollatable */ ;
1015 else if (inner_cxt.state != FDW_COLLATE_SAFE ||
1016 agg->inputcollid != inner_cxt.collation)
1017 return false;
1018
1019 /*
1020 * Detect whether node is introducing a collation not derived
1021 * from a foreign Var. (If so, we just mark it unsafe for now
1022 * rather than immediately returning false, since the parent
1023 * node might not care.)
1024 */
1025 collation = agg->aggcollid;
1026 if (collation == InvalidOid)
1028 else if (inner_cxt.state == FDW_COLLATE_SAFE &&
1029 collation == inner_cxt.collation)
1031 else if (collation == DEFAULT_COLLATION_OID)
1033 else
1035 }
1036 break;
1037 default:
1038
1039 /*
1040 * If it's anything else, assume it's unsafe. This list can be
1041 * expanded later, but don't forget to add deparse support below.
1042 */
1043 return false;
1044 }
1045
1046 /*
1047 * If result type of given expression is not shippable, it can't be sent
1048 * to remote because it might have incompatible semantics on remote side.
1049 */
1050 if (check_type && !is_shippable(exprType(node), TypeRelationId, fpinfo))
1051 return false;
1052
1053 /*
1054 * Now, merge my collation information into my parent's state.
1055 */
1056 if (state > outer_cxt->state)
1057 {
1058 /* Override previous parent state */
1059 outer_cxt->collation = collation;
1060 outer_cxt->state = state;
1061 }
1062 else if (state == outer_cxt->state)
1063 {
1064 /* Merge, or detect error if there's a collation conflict */
1065 switch (state)
1066 {
1067 case FDW_COLLATE_NONE:
1068 /* Nothing + nothing is still nothing */
1069 break;
1070 case FDW_COLLATE_SAFE:
1071 if (collation != outer_cxt->collation)
1072 {
1073 /*
1074 * Non-default collation always beats default.
1075 */
1076 if (outer_cxt->collation == DEFAULT_COLLATION_OID)
1077 {
1078 /* Override previous parent state */
1079 outer_cxt->collation = collation;
1080 }
1081 else if (collation != DEFAULT_COLLATION_OID)
1082 {
1083 /*
1084 * Conflict; show state as indeterminate. We don't
1085 * want to "return false" right away, since parent
1086 * node might not care about collation.
1087 */
1088 outer_cxt->state = FDW_COLLATE_UNSAFE;
1089 }
1090 }
1091 break;
1092 case FDW_COLLATE_UNSAFE:
1093 /* We're still conflicted ... */
1094 break;
1095 }
1096 }
1097
1098 /* It looks OK */
1099 return true;
1100}
1101
1102/*
1103 * Returns true if given expr is something we'd have to send the value of
1104 * to the foreign server.
1105 *
1106 * This should return true when the expression is a shippable node that
1107 * deparseExpr would add to context->params_list. Note that we don't care
1108 * if the expression *contains* such a node, only whether one appears at top
1109 * level. We need this to detect cases where setrefs.c would recognize a
1110 * false match between an fdw_exprs item (which came from the params_list)
1111 * and an entry in fdw_scan_tlist (which we're considering putting the given
1112 * expression into).
1113 */
1114bool
1116 RelOptInfo *baserel,
1117 Expr *expr)
1118{
1119 if (expr == NULL)
1120 return false;
1121
1122 switch (nodeTag(expr))
1123 {
1124 case T_Var:
1125 {
1126 /* It would have to be sent unless it's a foreign Var */
1127 Var *var = (Var *) expr;
1128 PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) (baserel->fdw_private);
1129 Relids relids;
1130
1131 if (IS_UPPER_REL(baserel))
1132 relids = fpinfo->outerrel->relids;
1133 else
1134 relids = baserel->relids;
1135
1136 if (bms_is_member(var->varno, relids) && var->varlevelsup == 0)
1137 return false; /* foreign Var, so not a param */
1138 else
1139 return true; /* it'd have to be a param */
1140 break;
1141 }
1142 case T_Param:
1143 /* Params always have to be sent to the foreign server */
1144 return true;
1145 default:
1146 break;
1147 }
1148 return false;
1149}
1150
1151/*
1152 * Returns true if it's safe to push down the sort expression described by
1153 * 'pathkey' to the foreign server.
1154 */
1155bool
1157 RelOptInfo *baserel,
1158 PathKey *pathkey)
1159{
1160 EquivalenceClass *pathkey_ec = pathkey->pk_eclass;
1161 PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) baserel->fdw_private;
1162
1163 /*
1164 * is_foreign_expr would detect volatile expressions as well, but checking
1165 * ec_has_volatile here saves some cycles.
1166 */
1167 if (pathkey_ec->ec_has_volatile)
1168 return false;
1169
1170 /* can't push down the sort if the pathkey's opfamily is not shippable */
1171 if (!is_shippable(pathkey->pk_opfamily, OperatorFamilyRelationId, fpinfo))
1172 return false;
1173
1174 /* can push if a suitable EC member exists */
1175 return (find_em_for_rel(root, pathkey_ec, baserel) != NULL);
1176}
1177
1178/*
1179 * Convert type OID + typmod info into a type name we can ship to the remote
1180 * server. Someplace else had better have verified that this type name is
1181 * expected to be known on the remote end.
1182 *
1183 * This is almost just format_type_with_typemod(), except that if left to its
1184 * own devices, that function will make schema-qualification decisions based
1185 * on the local search_path, which is wrong. We must schema-qualify all
1186 * type names that are not in pg_catalog. We assume here that built-in types
1187 * are all in pg_catalog and need not be qualified; otherwise, qualify.
1188 */
1189static char *
1190deparse_type_name(Oid type_oid, int32 typemod)
1191{
1193
1194 if (!is_builtin(type_oid))
1196
1197 return format_type_extended(type_oid, typemod, flags);
1198}
1199
1200/*
1201 * Build the targetlist for given relation to be deparsed as SELECT clause.
1202 *
1203 * The output targetlist contains the columns that need to be fetched from the
1204 * foreign server for the given relation. If foreignrel is an upper relation,
1205 * then the output targetlist can also contain expressions to be evaluated on
1206 * foreign server.
1207 */
1208List *
1210{
1211 List *tlist = NIL;
1212 PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
1213 ListCell *lc;
1214
1215 /*
1216 * For an upper relation, we have already built the target list while
1217 * checking shippability, so just return that.
1218 */
1219 if (IS_UPPER_REL(foreignrel))
1220 return fpinfo->grouped_tlist;
1221
1222 /*
1223 * We require columns specified in foreignrel->reltarget->exprs and those
1224 * required for evaluating the local conditions.
1225 */
1226 tlist = add_to_flat_tlist(tlist,
1227 pull_var_clause((Node *) foreignrel->reltarget->exprs,
1229 foreach(lc, fpinfo->local_conds)
1230 {
1232
1233 tlist = add_to_flat_tlist(tlist,
1234 pull_var_clause((Node *) rinfo->clause,
1236 }
1237
1238 return tlist;
1239}
1240
1241/*
1242 * Deparse SELECT statement for given relation into buf.
1243 *
1244 * tlist contains the list of desired columns to be fetched from foreign server.
1245 * For a base relation fpinfo->attrs_used is used to construct SELECT clause,
1246 * hence the tlist is ignored for a base relation.
1247 *
1248 * remote_conds is the list of conditions to be deparsed into the WHERE clause
1249 * (or, in the case of upper relations, into the HAVING clause).
1250 *
1251 * If params_list is not NULL, it receives a list of Params and other-relation
1252 * Vars used in the clauses; these values must be transmitted to the remote
1253 * server as parameter values.
1254 *
1255 * If params_list is NULL, we're generating the query for EXPLAIN purposes,
1256 * so Params and other-relation Vars should be replaced by dummy values.
1257 *
1258 * pathkeys is the list of pathkeys to order the result by.
1259 *
1260 * is_subquery is the flag to indicate whether to deparse the specified
1261 * relation as a subquery.
1262 *
1263 * List of columns selected is returned in retrieved_attrs.
1264 */
1265void
1267 List *tlist, List *remote_conds, List *pathkeys,
1268 bool has_final_sort, bool has_limit, bool is_subquery,
1269 List **retrieved_attrs, List **params_list)
1270{
1271 deparse_expr_cxt context;
1272 PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) rel->fdw_private;
1273 List *quals;
1274
1275 /*
1276 * We handle relations for foreign tables, joins between those and upper
1277 * relations.
1278 */
1279 Assert(IS_JOIN_REL(rel) || IS_SIMPLE_REL(rel) || IS_UPPER_REL(rel));
1280
1281 /* Fill portions of context common to upper, join and base relation */
1282 context.buf = buf;
1283 context.root = root;
1284 context.foreignrel = rel;
1285 context.scanrel = IS_UPPER_REL(rel) ? fpinfo->outerrel : rel;
1286 context.params_list = params_list;
1287
1288 /* Construct SELECT clause */
1289 deparseSelectSql(tlist, is_subquery, retrieved_attrs, &context);
1290
1291 /*
1292 * For upper relations, the WHERE clause is built from the remote
1293 * conditions of the underlying scan relation; otherwise, we can use the
1294 * supplied list of remote conditions directly.
1295 */
1296 if (IS_UPPER_REL(rel))
1297 {
1298 PgFdwRelationInfo *ofpinfo;
1299
1300 ofpinfo = (PgFdwRelationInfo *) fpinfo->outerrel->fdw_private;
1301 quals = ofpinfo->remote_conds;
1302 }
1303 else
1304 quals = remote_conds;
1305
1306 /* Construct FROM and WHERE clauses */
1307 deparseFromExpr(quals, &context);
1308
1309 if (IS_UPPER_REL(rel))
1310 {
1311 /* Append GROUP BY clause */
1312 appendGroupByClause(tlist, &context);
1313
1314 /* Append HAVING clause */
1315 if (remote_conds)
1316 {
1317 appendStringInfoString(buf, " HAVING ");
1318 appendConditions(remote_conds, &context);
1319 }
1320 }
1321
1322 /* Add ORDER BY clause if we found any useful pathkeys */
1323 if (pathkeys)
1324 appendOrderByClause(pathkeys, has_final_sort, &context);
1325
1326 /* Add LIMIT clause if necessary */
1327 if (has_limit)
1328 appendLimitClause(&context);
1329
1330 /* Add any necessary FOR UPDATE/SHARE. */
1331 deparseLockingClause(&context);
1332}
1333
1334/*
1335 * Construct a simple SELECT statement that retrieves desired columns
1336 * of the specified foreign table, and append it to "buf". The output
1337 * contains just "SELECT ... ".
1338 *
1339 * We also create an integer List of the columns being retrieved, which is
1340 * returned to *retrieved_attrs, unless we deparse the specified relation
1341 * as a subquery.
1342 *
1343 * tlist is the list of desired columns. is_subquery is the flag to
1344 * indicate whether to deparse the specified relation as a subquery.
1345 * Read prologue of deparseSelectStmtForRel() for details.
1346 */
1347static void
1348deparseSelectSql(List *tlist, bool is_subquery, List **retrieved_attrs,
1349 deparse_expr_cxt *context)
1350{
1351 StringInfo buf = context->buf;
1352 RelOptInfo *foreignrel = context->foreignrel;
1353 PlannerInfo *root = context->root;
1354 PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
1355
1356 /*
1357 * Construct SELECT list
1358 */
1359 appendStringInfoString(buf, "SELECT ");
1360
1361 if (is_subquery)
1362 {
1363 /*
1364 * For a relation that is deparsed as a subquery, emit expressions
1365 * specified in the relation's reltarget. Note that since this is for
1366 * the subquery, no need to care about *retrieved_attrs.
1367 */
1369 }
1370 else if (IS_JOIN_REL(foreignrel) || IS_UPPER_REL(foreignrel))
1371 {
1372 /*
1373 * For a join or upper relation the input tlist gives the list of
1374 * columns required to be fetched from the foreign server.
1375 */
1376 deparseExplicitTargetList(tlist, false, retrieved_attrs, context);
1377 }
1378 else
1379 {
1380 /*
1381 * For a base relation fpinfo->attrs_used gives the list of columns
1382 * required to be fetched from the foreign server.
1383 */
1384 RangeTblEntry *rte = planner_rt_fetch(foreignrel->relid, root);
1385
1386 /*
1387 * Core code already has some lock on each rel being planned, so we
1388 * can use NoLock here.
1389 */
1390 Relation rel = table_open(rte->relid, NoLock);
1391
1392 deparseTargetList(buf, rte, foreignrel->relid, rel, false,
1393 fpinfo->attrs_used, false, retrieved_attrs);
1394 table_close(rel, NoLock);
1395 }
1396}
1397
1398/*
1399 * Construct a FROM clause and, if needed, a WHERE clause, and append those to
1400 * "buf".
1401 *
1402 * quals is the list of clauses to be included in the WHERE clause.
1403 * (These may or may not include RestrictInfo decoration.)
1404 */
1405static void
1407{
1408 StringInfo buf = context->buf;
1409 RelOptInfo *scanrel = context->scanrel;
1410 List *additional_conds = NIL;
1411
1412 /* For upper relations, scanrel must be either a joinrel or a baserel */
1413 Assert(!IS_UPPER_REL(context->foreignrel) ||
1414 IS_JOIN_REL(scanrel) || IS_SIMPLE_REL(scanrel));
1415
1416 /* Construct FROM clause */
1417 appendStringInfoString(buf, " FROM ");
1418 deparseFromExprForRel(buf, context->root, scanrel,
1419 (bms_membership(scanrel->relids) == BMS_MULTIPLE),
1420 (Index) 0, NULL, &additional_conds,
1421 context->params_list);
1422 appendWhereClause(quals, additional_conds, context);
1423 if (additional_conds != NIL)
1424 list_free_deep(additional_conds);
1425}
1426
1427/*
1428 * Emit a target list that retrieves the columns specified in attrs_used.
1429 * This is used for both SELECT and RETURNING targetlists; the is_returning
1430 * parameter is true only for a RETURNING targetlist.
1431 *
1432 * The tlist text is appended to buf, and we also create an integer List
1433 * of the columns being retrieved, which is returned to *retrieved_attrs.
1434 *
1435 * If qualify_col is true, add relation alias before the column name.
1436 */
1437static void
1439 RangeTblEntry *rte,
1440 Index rtindex,
1441 Relation rel,
1442 bool is_returning,
1443 Bitmapset *attrs_used,
1444 bool qualify_col,
1445 List **retrieved_attrs)
1446{
1447 TupleDesc tupdesc = RelationGetDescr(rel);
1448 bool have_wholerow;
1449 bool first;
1450 int i;
1451
1452 *retrieved_attrs = NIL;
1453
1454 /* If there's a whole-row reference, we'll need all the columns. */
1456 attrs_used);
1457
1458 first = true;
1459 for (i = 1; i <= tupdesc->natts; i++)
1460 {
1461 Form_pg_attribute attr = TupleDescAttr(tupdesc, i - 1);
1462
1463 /* Ignore dropped attributes. */
1464 if (attr->attisdropped)
1465 continue;
1466
1467 if (have_wholerow ||
1469 attrs_used))
1470 {
1471 if (!first)
1473 else if (is_returning)
1474 appendStringInfoString(buf, " RETURNING ");
1475 first = false;
1476
1477 deparseColumnRef(buf, rtindex, i, rte, qualify_col);
1478
1479 *retrieved_attrs = lappend_int(*retrieved_attrs, i);
1480 }
1481 }
1482
1483 /*
1484 * Add ctid if needed. We currently don't support retrieving any other
1485 * system columns.
1486 */
1488 attrs_used))
1489 {
1490 if (!first)
1492 else if (is_returning)
1493 appendStringInfoString(buf, " RETURNING ");
1494 first = false;
1495
1496 if (qualify_col)
1497 ADD_REL_QUALIFIER(buf, rtindex);
1498 appendStringInfoString(buf, "ctid");
1499
1500 *retrieved_attrs = lappend_int(*retrieved_attrs,
1502 }
1503
1504 /* Don't generate bad syntax if no undropped columns */
1505 if (first && !is_returning)
1506 appendStringInfoString(buf, "NULL");
1507}
1508
1509/*
1510 * Deparse the appropriate locking clause (FOR UPDATE or FOR SHARE) for a
1511 * given relation (context->scanrel).
1512 */
1513static void
1515{
1516 StringInfo buf = context->buf;
1517 PlannerInfo *root = context->root;
1518 RelOptInfo *rel = context->scanrel;
1519 PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) rel->fdw_private;
1520 int relid = -1;
1521
1522 while ((relid = bms_next_member(rel->relids, relid)) >= 0)
1523 {
1524 /*
1525 * Ignore relation if it appears in a lower subquery. Locking clause
1526 * for such a relation is included in the subquery if necessary.
1527 */
1528 if (bms_is_member(relid, fpinfo->lower_subquery_rels))
1529 continue;
1530
1531 /*
1532 * Add FOR UPDATE/SHARE if appropriate. We apply locking during the
1533 * initial row fetch, rather than later on as is done for local
1534 * tables. The extra roundtrips involved in trying to duplicate the
1535 * local semantics exactly don't seem worthwhile (see also comments
1536 * for RowMarkType).
1537 *
1538 * Note: because we actually run the query as a cursor, this assumes
1539 * that DECLARE CURSOR ... FOR UPDATE is supported, which it isn't
1540 * before 8.3.
1541 */
1542 if (bms_is_member(relid, root->all_result_relids) &&
1543 (root->parse->commandType == CMD_UPDATE ||
1544 root->parse->commandType == CMD_DELETE))
1545 {
1546 /* Relation is UPDATE/DELETE target, so use FOR UPDATE */
1547 appendStringInfoString(buf, " FOR UPDATE");
1548
1549 /* Add the relation alias if we are here for a join relation */
1550 if (IS_JOIN_REL(rel))
1551 appendStringInfo(buf, " OF %s%d", REL_ALIAS_PREFIX, relid);
1552 }
1553 else
1554 {
1555 PlanRowMark *rc = get_plan_rowmark(root->rowMarks, relid);
1556
1557 if (rc)
1558 {
1559 /*
1560 * Relation is specified as a FOR UPDATE/SHARE target, so
1561 * handle that. (But we could also see LCS_NONE, meaning this
1562 * isn't a target relation after all.)
1563 *
1564 * For now, just ignore any [NO] KEY specification, since (a)
1565 * it's not clear what that means for a remote table that we
1566 * don't have complete information about, and (b) it wouldn't
1567 * work anyway on older remote servers. Likewise, we don't
1568 * worry about NOWAIT.
1569 */
1570 switch (rc->strength)
1571 {
1572 case LCS_NONE:
1573 /* No locking needed */
1574 break;
1575 case LCS_FORKEYSHARE:
1576 case LCS_FORSHARE:
1577 appendStringInfoString(buf, " FOR SHARE");
1578 break;
1579 case LCS_FORNOKEYUPDATE:
1580 case LCS_FORUPDATE:
1581 appendStringInfoString(buf, " FOR UPDATE");
1582 break;
1583 }
1584
1585 /* Add the relation alias if we are here for a join relation */
1586 if (bms_membership(rel->relids) == BMS_MULTIPLE &&
1587 rc->strength != LCS_NONE)
1588 appendStringInfo(buf, " OF %s%d", REL_ALIAS_PREFIX, relid);
1589 }
1590 }
1591 }
1592}
1593
1594/*
1595 * Deparse conditions from the provided list and append them to buf.
1596 *
1597 * The conditions in the list are assumed to be ANDed. This function is used to
1598 * deparse WHERE clauses, JOIN .. ON clauses and HAVING clauses.
1599 *
1600 * Depending on the caller, the list elements might be either RestrictInfos
1601 * or bare clauses.
1602 */
1603static void
1605{
1606 int nestlevel;
1607 ListCell *lc;
1608 bool is_first = true;
1609 StringInfo buf = context->buf;
1610
1611 /* Make sure any constants in the exprs are printed portably */
1612 nestlevel = set_transmission_modes();
1613
1614 foreach(lc, exprs)
1615 {
1616 Expr *expr = (Expr *) lfirst(lc);
1617
1618 /* Extract clause from RestrictInfo, if required */
1619 if (IsA(expr, RestrictInfo))
1620 expr = ((RestrictInfo *) expr)->clause;
1621
1622 /* Connect expressions with "AND" and parenthesize each condition. */
1623 if (!is_first)
1624 appendStringInfoString(buf, " AND ");
1625
1627 deparseExpr(expr, context);
1629
1630 is_first = false;
1631 }
1632
1633 reset_transmission_modes(nestlevel);
1634}
1635
1636/*
1637 * Append WHERE clause, containing conditions from exprs and additional_conds,
1638 * to context->buf.
1639 */
1640static void
1641appendWhereClause(List *exprs, List *additional_conds, deparse_expr_cxt *context)
1642{
1643 StringInfo buf = context->buf;
1644 bool need_and = false;
1645 ListCell *lc;
1646
1647 if (exprs != NIL || additional_conds != NIL)
1648 appendStringInfoString(buf, " WHERE ");
1649
1650 /*
1651 * If there are some filters, append them.
1652 */
1653 if (exprs != NIL)
1654 {
1655 appendConditions(exprs, context);
1656 need_and = true;
1657 }
1658
1659 /*
1660 * If there are some EXISTS conditions, coming from SEMI-JOINS, append
1661 * them.
1662 */
1663 foreach(lc, additional_conds)
1664 {
1665 if (need_and)
1666 appendStringInfoString(buf, " AND ");
1667 appendStringInfoString(buf, (char *) lfirst(lc));
1668 need_and = true;
1669 }
1670}
1671
1672/* Output join name for given join type */
1673const char *
1675{
1676 switch (jointype)
1677 {
1678 case JOIN_INNER:
1679 return "INNER";
1680
1681 case JOIN_LEFT:
1682 return "LEFT";
1683
1684 case JOIN_RIGHT:
1685 return "RIGHT";
1686
1687 case JOIN_FULL:
1688 return "FULL";
1689
1690 case JOIN_SEMI:
1691 return "SEMI";
1692
1693 default:
1694 /* Shouldn't come here, but protect from buggy code. */
1695 elog(ERROR, "unsupported join type %d", jointype);
1696 }
1697
1698 /* Keep compiler happy */
1699 return NULL;
1700}
1701
1702/*
1703 * Deparse given targetlist and append it to context->buf.
1704 *
1705 * tlist is list of TargetEntry's which in turn contain Var nodes.
1706 *
1707 * retrieved_attrs is the list of continuously increasing integers starting
1708 * from 1. It has same number of entries as tlist.
1709 *
1710 * This is used for both SELECT and RETURNING targetlists; the is_returning
1711 * parameter is true only for a RETURNING targetlist.
1712 */
1713static void
1715 bool is_returning,
1716 List **retrieved_attrs,
1717 deparse_expr_cxt *context)
1718{
1719 ListCell *lc;
1720 StringInfo buf = context->buf;
1721 int i = 0;
1722
1723 *retrieved_attrs = NIL;
1724
1725 foreach(lc, tlist)
1726 {
1728
1729 if (i > 0)
1731 else if (is_returning)
1732 appendStringInfoString(buf, " RETURNING ");
1733
1734 deparseExpr((Expr *) tle->expr, context);
1735
1736 *retrieved_attrs = lappend_int(*retrieved_attrs, i + 1);
1737 i++;
1738 }
1739
1740 if (i == 0 && !is_returning)
1741 appendStringInfoString(buf, "NULL");
1742}
1743
1744/*
1745 * Emit expressions specified in the given relation's reltarget.
1746 *
1747 * This is used for deparsing the given relation as a subquery.
1748 */
1749static void
1751{
1752 StringInfo buf = context->buf;
1753 RelOptInfo *foreignrel = context->foreignrel;
1754 bool first;
1755 ListCell *lc;
1756
1757 /* Should only be called in these cases. */
1758 Assert(IS_SIMPLE_REL(foreignrel) || IS_JOIN_REL(foreignrel));
1759
1760 first = true;
1761 foreach(lc, foreignrel->reltarget->exprs)
1762 {
1763 Node *node = (Node *) lfirst(lc);
1764
1765 if (!first)
1767 first = false;
1768
1769 deparseExpr((Expr *) node, context);
1770 }
1771
1772 /* Don't generate bad syntax if no expressions */
1773 if (first)
1774 appendStringInfoString(buf, "NULL");
1775}
1776
1777/*
1778 * Construct FROM clause for given relation
1779 *
1780 * The function constructs ... JOIN ... ON ... for join relation. For a base
1781 * relation it just returns schema-qualified tablename, with the appropriate
1782 * alias if so requested.
1783 *
1784 * 'ignore_rel' is either zero or the RT index of a target relation. In the
1785 * latter case the function constructs FROM clause of UPDATE or USING clause
1786 * of DELETE; it deparses the join relation as if the relation never contained
1787 * the target relation, and creates a List of conditions to be deparsed into
1788 * the top-level WHERE clause, which is returned to *ignore_conds.
1789 *
1790 * 'additional_conds' is a pointer to a list of strings to be appended to
1791 * the WHERE clause, coming from lower-level SEMI-JOINs.
1792 */
1793static void
1795 bool use_alias, Index ignore_rel, List **ignore_conds,
1796 List **additional_conds, List **params_list)
1797{
1798 PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
1799
1800 if (IS_JOIN_REL(foreignrel))
1801 {
1802 StringInfoData join_sql_o;
1803 StringInfoData join_sql_i;
1804 RelOptInfo *outerrel = fpinfo->outerrel;
1805 RelOptInfo *innerrel = fpinfo->innerrel;
1806 bool outerrel_is_target = false;
1807 bool innerrel_is_target = false;
1808 List *additional_conds_i = NIL;
1809 List *additional_conds_o = NIL;
1810
1811 if (ignore_rel > 0 && bms_is_member(ignore_rel, foreignrel->relids))
1812 {
1813 /*
1814 * If this is an inner join, add joinclauses to *ignore_conds and
1815 * set it to empty so that those can be deparsed into the WHERE
1816 * clause. Note that since the target relation can never be
1817 * within the nullable side of an outer join, those could safely
1818 * be pulled up into the WHERE clause (see foreign_join_ok()).
1819 * Note also that since the target relation is only inner-joined
1820 * to any other relation in the query, all conditions in the join
1821 * tree mentioning the target relation could be deparsed into the
1822 * WHERE clause by doing this recursively.
1823 */
1824 if (fpinfo->jointype == JOIN_INNER)
1825 {
1826 *ignore_conds = list_concat(*ignore_conds,
1827 fpinfo->joinclauses);
1828 fpinfo->joinclauses = NIL;
1829 }
1830
1831 /*
1832 * Check if either of the input relations is the target relation.
1833 */
1834 if (outerrel->relid == ignore_rel)
1835 outerrel_is_target = true;
1836 else if (innerrel->relid == ignore_rel)
1837 innerrel_is_target = true;
1838 }
1839
1840 /* Deparse outer relation if not the target relation. */
1841 if (!outerrel_is_target)
1842 {
1843 initStringInfo(&join_sql_o);
1844 deparseRangeTblRef(&join_sql_o, root, outerrel,
1845 fpinfo->make_outerrel_subquery,
1846 ignore_rel, ignore_conds, &additional_conds_o,
1847 params_list);
1848
1849 /*
1850 * If inner relation is the target relation, skip deparsing it.
1851 * Note that since the join of the target relation with any other
1852 * relation in the query is an inner join and can never be within
1853 * the nullable side of an outer join, the join could be
1854 * interchanged with higher-level joins (cf. identity 1 on outer
1855 * join reordering shown in src/backend/optimizer/README), which
1856 * means it's safe to skip the target-relation deparsing here.
1857 */
1858 if (innerrel_is_target)
1859 {
1860 Assert(fpinfo->jointype == JOIN_INNER);
1861 Assert(fpinfo->joinclauses == NIL);
1862 appendBinaryStringInfo(buf, join_sql_o.data, join_sql_o.len);
1863 /* Pass EXISTS conditions to upper level */
1864 if (additional_conds_o != NIL)
1865 {
1866 Assert(*additional_conds == NIL);
1867 *additional_conds = additional_conds_o;
1868 }
1869 return;
1870 }
1871 }
1872
1873 /* Deparse inner relation if not the target relation. */
1874 if (!innerrel_is_target)
1875 {
1876 initStringInfo(&join_sql_i);
1877 deparseRangeTblRef(&join_sql_i, root, innerrel,
1878 fpinfo->make_innerrel_subquery,
1879 ignore_rel, ignore_conds, &additional_conds_i,
1880 params_list);
1881
1882 /*
1883 * SEMI-JOIN is deparsed as the EXISTS subquery. It references
1884 * outer and inner relations, so it should be evaluated as the
1885 * condition in the upper-level WHERE clause. We deparse the
1886 * condition and pass it to upper level callers as an
1887 * additional_conds list. Upper level callers are responsible for
1888 * inserting conditions from the list where appropriate.
1889 */
1890 if (fpinfo->jointype == JOIN_SEMI)
1891 {
1892 deparse_expr_cxt context;
1894
1895 /* Construct deparsed condition from this SEMI-JOIN */
1897 appendStringInfo(&str, "EXISTS (SELECT NULL FROM %s",
1898 join_sql_i.data);
1899
1900 context.buf = &str;
1901 context.foreignrel = foreignrel;
1902 context.scanrel = foreignrel;
1903 context.root = root;
1904 context.params_list = params_list;
1905
1906 /*
1907 * Append SEMI-JOIN clauses and EXISTS conditions from lower
1908 * levels to the current EXISTS subquery
1909 */
1910 appendWhereClause(fpinfo->joinclauses, additional_conds_i, &context);
1911
1912 /*
1913 * EXISTS conditions, coming from lower join levels, have just
1914 * been processed.
1915 */
1916 if (additional_conds_i != NIL)
1917 {
1918 list_free_deep(additional_conds_i);
1919 additional_conds_i = NIL;
1920 }
1921
1922 /* Close parentheses for EXISTS subquery */
1924
1925 *additional_conds = lappend(*additional_conds, str.data);
1926 }
1927
1928 /*
1929 * If outer relation is the target relation, skip deparsing it.
1930 * See the above note about safety.
1931 */
1932 if (outerrel_is_target)
1933 {
1934 Assert(fpinfo->jointype == JOIN_INNER);
1935 Assert(fpinfo->joinclauses == NIL);
1936 appendBinaryStringInfo(buf, join_sql_i.data, join_sql_i.len);
1937 /* Pass EXISTS conditions to the upper call */
1938 if (additional_conds_i != NIL)
1939 {
1940 Assert(*additional_conds == NIL);
1941 *additional_conds = additional_conds_i;
1942 }
1943 return;
1944 }
1945 }
1946
1947 /* Neither of the relations is the target relation. */
1948 Assert(!outerrel_is_target && !innerrel_is_target);
1949
1950 /*
1951 * For semijoin FROM clause is deparsed as an outer relation. An inner
1952 * relation and join clauses are converted to EXISTS condition and
1953 * passed to the upper level.
1954 */
1955 if (fpinfo->jointype == JOIN_SEMI)
1956 {
1957 appendBinaryStringInfo(buf, join_sql_o.data, join_sql_o.len);
1958 }
1959 else
1960 {
1961 /*
1962 * For a join relation FROM clause, entry is deparsed as
1963 *
1964 * ((outer relation) <join type> (inner relation) ON
1965 * (joinclauses))
1966 */
1967 appendStringInfo(buf, "(%s %s JOIN %s ON ", join_sql_o.data,
1968 get_jointype_name(fpinfo->jointype), join_sql_i.data);
1969
1970 /* Append join clause; (TRUE) if no join clause */
1971 if (fpinfo->joinclauses)
1972 {
1973 deparse_expr_cxt context;
1974
1975 context.buf = buf;
1976 context.foreignrel = foreignrel;
1977 context.scanrel = foreignrel;
1978 context.root = root;
1979 context.params_list = params_list;
1980
1982 appendConditions(fpinfo->joinclauses, &context);
1984 }
1985 else
1986 appendStringInfoString(buf, "(TRUE)");
1987
1988 /* End the FROM clause entry. */
1990 }
1991
1992 /*
1993 * Construct additional_conds to be passed to the upper caller from
1994 * current level additional_conds and additional_conds, coming from
1995 * inner and outer rels.
1996 */
1997 if (additional_conds_o != NIL)
1998 {
1999 *additional_conds = list_concat(*additional_conds,
2000 additional_conds_o);
2001 list_free(additional_conds_o);
2002 }
2003
2004 if (additional_conds_i != NIL)
2005 {
2006 *additional_conds = list_concat(*additional_conds,
2007 additional_conds_i);
2008 list_free(additional_conds_i);
2009 }
2010 }
2011 else
2012 {
2013 RangeTblEntry *rte = planner_rt_fetch(foreignrel->relid, root);
2014
2015 /*
2016 * Core code already has some lock on each rel being planned, so we
2017 * can use NoLock here.
2018 */
2019 Relation rel = table_open(rte->relid, NoLock);
2020
2021 deparseRelation(buf, rel);
2022
2023 /*
2024 * Add a unique alias to avoid any conflict in relation names due to
2025 * pulled up subqueries in the query being built for a pushed down
2026 * join.
2027 */
2028 if (use_alias)
2029 appendStringInfo(buf, " %s%d", REL_ALIAS_PREFIX, foreignrel->relid);
2030
2031 table_close(rel, NoLock);
2032 }
2033}
2034
2035/*
2036 * Append FROM clause entry for the given relation into buf.
2037 * Conditions from lower-level SEMI-JOINs are appended to additional_conds
2038 * and should be added to upper level WHERE clause.
2039 */
2040static void
2042 bool make_subquery, Index ignore_rel, List **ignore_conds,
2043 List **additional_conds, List **params_list)
2044{
2045 PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
2046
2047 /* Should only be called in these cases. */
2048 Assert(IS_SIMPLE_REL(foreignrel) || IS_JOIN_REL(foreignrel));
2049
2050 Assert(fpinfo->local_conds == NIL);
2051
2052 /* If make_subquery is true, deparse the relation as a subquery. */
2053 if (make_subquery)
2054 {
2055 List *retrieved_attrs;
2056 int ncols;
2057
2058 /*
2059 * The given relation shouldn't contain the target relation, because
2060 * this should only happen for input relations for a full join, and
2061 * such relations can never contain an UPDATE/DELETE target.
2062 */
2063 Assert(ignore_rel == 0 ||
2064 !bms_is_member(ignore_rel, foreignrel->relids));
2065
2066 /* Deparse the subquery representing the relation. */
2068 deparseSelectStmtForRel(buf, root, foreignrel, NIL,
2069 fpinfo->remote_conds, NIL,
2070 false, false, true,
2071 &retrieved_attrs, params_list);
2073
2074 /* Append the relation alias. */
2076 fpinfo->relation_index);
2077
2078 /*
2079 * Append the column aliases if needed. Note that the subquery emits
2080 * expressions specified in the relation's reltarget (see
2081 * deparseSubqueryTargetList).
2082 */
2083 ncols = list_length(foreignrel->reltarget->exprs);
2084 if (ncols > 0)
2085 {
2086 int i;
2087
2089 for (i = 1; i <= ncols; i++)
2090 {
2091 if (i > 1)
2093
2095 }
2097 }
2098 }
2099 else
2100 deparseFromExprForRel(buf, root, foreignrel, true, ignore_rel,
2101 ignore_conds, additional_conds,
2102 params_list);
2103}
2104
2105/*
2106 * deparse remote INSERT statement
2107 *
2108 * The statement text is appended to buf, and we also create an integer List
2109 * of the columns being retrieved by WITH CHECK OPTION or RETURNING (if any),
2110 * which is returned to *retrieved_attrs.
2111 *
2112 * This also stores end position of the VALUES clause, so that we can rebuild
2113 * an INSERT for a batch of rows later.
2114 */
2115void
2117 Index rtindex, Relation rel,
2118 List *targetAttrs, bool doNothing,
2119 List *withCheckOptionList, List *returningList,
2120 List **retrieved_attrs, int *values_end_len)
2121{
2122 TupleDesc tupdesc = RelationGetDescr(rel);
2123 AttrNumber pindex;
2124 bool first;
2125 ListCell *lc;
2126
2127 appendStringInfoString(buf, "INSERT INTO ");
2128 deparseRelation(buf, rel);
2129
2130 if (targetAttrs)
2131 {
2133
2134 first = true;
2135 foreach(lc, targetAttrs)
2136 {
2137 int attnum = lfirst_int(lc);
2138
2139 if (!first)
2141 first = false;
2142
2143 deparseColumnRef(buf, rtindex, attnum, rte, false);
2144 }
2145
2146 appendStringInfoString(buf, ") VALUES (");
2147
2148 pindex = 1;
2149 first = true;
2150 foreach(lc, targetAttrs)
2151 {
2152 int attnum = lfirst_int(lc);
2153 Form_pg_attribute attr = TupleDescAttr(tupdesc, attnum - 1);
2154
2155 if (!first)
2157 first = false;
2158
2159 if (attr->attgenerated)
2160 appendStringInfoString(buf, "DEFAULT");
2161 else
2162 {
2163 appendStringInfo(buf, "$%d", pindex);
2164 pindex++;
2165 }
2166 }
2167
2169 }
2170 else
2171 appendStringInfoString(buf, " DEFAULT VALUES");
2172 *values_end_len = buf->len;
2173
2174 if (doNothing)
2175 appendStringInfoString(buf, " ON CONFLICT DO NOTHING");
2176
2177 deparseReturningList(buf, rte, rtindex, rel,
2179 withCheckOptionList, returningList, retrieved_attrs);
2180}
2181
2182/*
2183 * rebuild remote INSERT statement
2184 *
2185 * Provided a number of rows in a batch, builds INSERT statement with the
2186 * right number of parameters.
2187 */
2188void
2190 char *orig_query, List *target_attrs,
2191 int values_end_len, int num_params,
2192 int num_rows)
2193{
2194 TupleDesc tupdesc = RelationGetDescr(rel);
2195 int i;
2196 int pindex;
2197 bool first;
2198 ListCell *lc;
2199
2200 /* Make sure the values_end_len is sensible */
2201 Assert((values_end_len > 0) && (values_end_len <= strlen(orig_query)));
2202
2203 /* Copy up to the end of the first record from the original query */
2204 appendBinaryStringInfo(buf, orig_query, values_end_len);
2205
2206 /*
2207 * Add records to VALUES clause (we already have parameters for the first
2208 * row, so start at the right offset).
2209 */
2210 pindex = num_params + 1;
2211 for (i = 0; i < num_rows; i++)
2212 {
2214
2215 first = true;
2216 foreach(lc, target_attrs)
2217 {
2218 int attnum = lfirst_int(lc);
2219 Form_pg_attribute attr = TupleDescAttr(tupdesc, attnum - 1);
2220
2221 if (!first)
2223 first = false;
2224
2225 if (attr->attgenerated)
2226 appendStringInfoString(buf, "DEFAULT");
2227 else
2228 {
2229 appendStringInfo(buf, "$%d", pindex);
2230 pindex++;
2231 }
2232 }
2233
2235 }
2236
2237 /* Copy stuff after VALUES clause from the original query */
2238 appendStringInfoString(buf, orig_query + values_end_len);
2239}
2240
2241/*
2242 * deparse remote UPDATE statement
2243 *
2244 * The statement text is appended to buf, and we also create an integer List
2245 * of the columns being retrieved by WITH CHECK OPTION or RETURNING (if any),
2246 * which is returned to *retrieved_attrs.
2247 */
2248void
2250 Index rtindex, Relation rel,
2251 List *targetAttrs,
2252 List *withCheckOptionList, List *returningList,
2253 List **retrieved_attrs)
2254{
2255 TupleDesc tupdesc = RelationGetDescr(rel);
2256 AttrNumber pindex;
2257 bool first;
2258 ListCell *lc;
2259
2260 appendStringInfoString(buf, "UPDATE ");
2261 deparseRelation(buf, rel);
2262 appendStringInfoString(buf, " SET ");
2263
2264 pindex = 2; /* ctid is always the first param */
2265 first = true;
2266 foreach(lc, targetAttrs)
2267 {
2268 int attnum = lfirst_int(lc);
2269 Form_pg_attribute attr = TupleDescAttr(tupdesc, attnum - 1);
2270
2271 if (!first)
2273 first = false;
2274
2275 deparseColumnRef(buf, rtindex, attnum, rte, false);
2276 if (attr->attgenerated)
2277 appendStringInfoString(buf, " = DEFAULT");
2278 else
2279 {
2280 appendStringInfo(buf, " = $%d", pindex);
2281 pindex++;
2282 }
2283 }
2284 appendStringInfoString(buf, " WHERE ctid = $1");
2285
2286 deparseReturningList(buf, rte, rtindex, rel,
2288 withCheckOptionList, returningList, retrieved_attrs);
2289}
2290
2291/*
2292 * deparse remote UPDATE statement
2293 *
2294 * 'buf' is the output buffer to append the statement to
2295 * 'rtindex' is the RT index of the associated target relation
2296 * 'rel' is the relation descriptor for the target relation
2297 * 'foreignrel' is the RelOptInfo for the target relation or the join relation
2298 * containing all base relations in the query
2299 * 'targetlist' is the tlist of the underlying foreign-scan plan node
2300 * (note that this only contains new-value expressions and junk attrs)
2301 * 'targetAttrs' is the target columns of the UPDATE
2302 * 'remote_conds' is the qual clauses that must be evaluated remotely
2303 * '*params_list' is an output list of exprs that will become remote Params
2304 * 'returningList' is the RETURNING targetlist
2305 * '*retrieved_attrs' is an output list of integers of columns being retrieved
2306 * by RETURNING (if any)
2307 */
2308void
2310 Index rtindex, Relation rel,
2311 RelOptInfo *foreignrel,
2312 List *targetlist,
2313 List *targetAttrs,
2314 List *remote_conds,
2315 List **params_list,
2316 List *returningList,
2317 List **retrieved_attrs)
2318{
2319 deparse_expr_cxt context;
2320 int nestlevel;
2321 bool first;
2322 RangeTblEntry *rte = planner_rt_fetch(rtindex, root);
2323 ListCell *lc,
2324 *lc2;
2325 List *additional_conds = NIL;
2326
2327 /* Set up context struct for recursion */
2328 context.root = root;
2329 context.foreignrel = foreignrel;
2330 context.scanrel = foreignrel;
2331 context.buf = buf;
2332 context.params_list = params_list;
2333
2334 appendStringInfoString(buf, "UPDATE ");
2335 deparseRelation(buf, rel);
2336 if (foreignrel->reloptkind == RELOPT_JOINREL)
2337 appendStringInfo(buf, " %s%d", REL_ALIAS_PREFIX, rtindex);
2338 appendStringInfoString(buf, " SET ");
2339
2340 /* Make sure any constants in the exprs are printed portably */
2341 nestlevel = set_transmission_modes();
2342
2343 first = true;
2344 forboth(lc, targetlist, lc2, targetAttrs)
2345 {
2347 int attnum = lfirst_int(lc2);
2348
2349 /* update's new-value expressions shouldn't be resjunk */
2350 Assert(!tle->resjunk);
2351
2352 if (!first)
2354 first = false;
2355
2356 deparseColumnRef(buf, rtindex, attnum, rte, false);
2358 deparseExpr((Expr *) tle->expr, &context);
2359 }
2360
2361 reset_transmission_modes(nestlevel);
2362
2363 if (foreignrel->reloptkind == RELOPT_JOINREL)
2364 {
2365 List *ignore_conds = NIL;
2366
2367
2368 appendStringInfoString(buf, " FROM ");
2369 deparseFromExprForRel(buf, root, foreignrel, true, rtindex,
2370 &ignore_conds, &additional_conds, params_list);
2371 remote_conds = list_concat(remote_conds, ignore_conds);
2372 }
2373
2374 appendWhereClause(remote_conds, additional_conds, &context);
2375
2376 if (additional_conds != NIL)
2377 list_free_deep(additional_conds);
2378
2379 if (foreignrel->reloptkind == RELOPT_JOINREL)
2380 deparseExplicitTargetList(returningList, true, retrieved_attrs,
2381 &context);
2382 else
2383 deparseReturningList(buf, rte, rtindex, rel, false,
2384 NIL, returningList, retrieved_attrs);
2385}
2386
2387/*
2388 * deparse remote DELETE statement
2389 *
2390 * The statement text is appended to buf, and we also create an integer List
2391 * of the columns being retrieved by RETURNING (if any), which is returned
2392 * to *retrieved_attrs.
2393 */
2394void
2396 Index rtindex, Relation rel,
2397 List *returningList,
2398 List **retrieved_attrs)
2399{
2400 appendStringInfoString(buf, "DELETE FROM ");
2401 deparseRelation(buf, rel);
2402 appendStringInfoString(buf, " WHERE ctid = $1");
2403
2404 deparseReturningList(buf, rte, rtindex, rel,
2406 NIL, returningList, retrieved_attrs);
2407}
2408
2409/*
2410 * deparse remote DELETE statement
2411 *
2412 * 'buf' is the output buffer to append the statement to
2413 * 'rtindex' is the RT index of the associated target relation
2414 * 'rel' is the relation descriptor for the target relation
2415 * 'foreignrel' is the RelOptInfo for the target relation or the join relation
2416 * containing all base relations in the query
2417 * 'remote_conds' is the qual clauses that must be evaluated remotely
2418 * '*params_list' is an output list of exprs that will become remote Params
2419 * 'returningList' is the RETURNING targetlist
2420 * '*retrieved_attrs' is an output list of integers of columns being retrieved
2421 * by RETURNING (if any)
2422 */
2423void
2425 Index rtindex, Relation rel,
2426 RelOptInfo *foreignrel,
2427 List *remote_conds,
2428 List **params_list,
2429 List *returningList,
2430 List **retrieved_attrs)
2431{
2432 deparse_expr_cxt context;
2433 List *additional_conds = NIL;
2434
2435 /* Set up context struct for recursion */
2436 context.root = root;
2437 context.foreignrel = foreignrel;
2438 context.scanrel = foreignrel;
2439 context.buf = buf;
2440 context.params_list = params_list;
2441
2442 appendStringInfoString(buf, "DELETE FROM ");
2443 deparseRelation(buf, rel);
2444 if (foreignrel->reloptkind == RELOPT_JOINREL)
2445 appendStringInfo(buf, " %s%d", REL_ALIAS_PREFIX, rtindex);
2446
2447 if (foreignrel->reloptkind == RELOPT_JOINREL)
2448 {
2449 List *ignore_conds = NIL;
2450
2451 appendStringInfoString(buf, " USING ");
2452 deparseFromExprForRel(buf, root, foreignrel, true, rtindex,
2453 &ignore_conds, &additional_conds, params_list);
2454 remote_conds = list_concat(remote_conds, ignore_conds);
2455 }
2456
2457 appendWhereClause(remote_conds, additional_conds, &context);
2458
2459 if (additional_conds != NIL)
2460 list_free_deep(additional_conds);
2461
2462 if (foreignrel->reloptkind == RELOPT_JOINREL)
2463 deparseExplicitTargetList(returningList, true, retrieved_attrs,
2464 &context);
2465 else
2467 rtindex, rel, false,
2468 NIL, returningList, retrieved_attrs);
2469}
2470
2471/*
2472 * Add a RETURNING clause, if needed, to an INSERT/UPDATE/DELETE.
2473 */
2474static void
2476 Index rtindex, Relation rel,
2477 bool trig_after_row,
2478 List *withCheckOptionList,
2479 List *returningList,
2480 List **retrieved_attrs)
2481{
2482 Bitmapset *attrs_used = NULL;
2483
2484 if (trig_after_row)
2485 {
2486 /* whole-row reference acquires all non-system columns */
2487 attrs_used =
2489 }
2490
2491 if (withCheckOptionList != NIL)
2492 {
2493 /*
2494 * We need the attrs, non-system and system, mentioned in the local
2495 * query's WITH CHECK OPTION list.
2496 *
2497 * Note: we do this to ensure that WCO constraints will be evaluated
2498 * on the data actually inserted/updated on the remote side, which
2499 * might differ from the data supplied by the core code, for example
2500 * as a result of remote triggers.
2501 */
2502 pull_varattnos((Node *) withCheckOptionList, rtindex,
2503 &attrs_used);
2504 }
2505
2506 if (returningList != NIL)
2507 {
2508 /*
2509 * We need the attrs, non-system and system, mentioned in the local
2510 * query's RETURNING list.
2511 */
2512 pull_varattnos((Node *) returningList, rtindex,
2513 &attrs_used);
2514 }
2515
2516 if (attrs_used != NULL)
2517 deparseTargetList(buf, rte, rtindex, rel, true, attrs_used, false,
2518 retrieved_attrs);
2519 else
2520 *retrieved_attrs = NIL;
2521}
2522
2523/*
2524 * Construct SELECT statement to acquire size in blocks of given relation.
2525 *
2526 * Note: we use local definition of block size, not remote definition.
2527 * This is perhaps debatable.
2528 *
2529 * Note: pg_relation_size() exists in 8.1 and later.
2530 */
2531void
2533{
2535
2536 /* We'll need the remote relation name as a literal. */
2538 deparseRelation(&relname, rel);
2539
2540 appendStringInfoString(buf, "SELECT pg_catalog.pg_relation_size(");
2542 appendStringInfo(buf, "::pg_catalog.regclass) / %d", BLCKSZ);
2543}
2544
2545/*
2546 * Construct SELECT statement to acquire the number of rows and the relkind of
2547 * a relation.
2548 *
2549 * Note: we just return the remote server's reltuples value, which might
2550 * be off a good deal, but it doesn't seem worth working harder. See
2551 * comments in postgresAcquireSampleRowsFunc.
2552 */
2553void
2555{
2557
2558 /* We'll need the remote relation name as a literal. */
2560 deparseRelation(&relname, rel);
2561
2562 appendStringInfoString(buf, "SELECT reltuples, relkind FROM pg_catalog.pg_class WHERE oid = ");
2564 appendStringInfoString(buf, "::pg_catalog.regclass");
2565}
2566
2567/*
2568 * Construct SELECT statement to acquire sample rows of given relation.
2569 *
2570 * SELECT command is appended to buf, and list of columns retrieved
2571 * is returned to *retrieved_attrs.
2572 *
2573 * We only support sampling methods we can decide based on server version.
2574 * Allowing custom TSM modules (like tsm_system_rows) might be useful, but it
2575 * would require detecting which extensions are installed, to allow automatic
2576 * fall-back. Moreover, the methods may use different parameters like number
2577 * of rows (and not sampling rate). So we leave this for future improvements.
2578 *
2579 * Using random() to sample rows on the remote server has the advantage that
2580 * this works on all PostgreSQL versions (unlike TABLESAMPLE), and that it
2581 * does the sampling on the remote side (without transferring everything and
2582 * then discarding most rows).
2583 *
2584 * The disadvantage is that we still have to read all rows and evaluate the
2585 * random(), while TABLESAMPLE (at least with the "system" method) may skip.
2586 * It's not that different from the "bernoulli" method, though.
2587 *
2588 * We could also do "ORDER BY random() LIMIT x", which would always pick
2589 * the expected number of rows, but it requires sorting so it may be much
2590 * more expensive (particularly on large tables, which is what the
2591 * remote sampling is meant to improve).
2592 */
2593void
2595 PgFdwSamplingMethod sample_method, double sample_frac,
2596 List **retrieved_attrs)
2597{
2598 Oid relid = RelationGetRelid(rel);
2599 TupleDesc tupdesc = RelationGetDescr(rel);
2600 int i;
2601 char *colname;
2602 List *options;
2603 ListCell *lc;
2604 bool first = true;
2605
2606 *retrieved_attrs = NIL;
2607
2608 appendStringInfoString(buf, "SELECT ");
2609 for (i = 0; i < tupdesc->natts; i++)
2610 {
2611 /* Ignore dropped columns. */
2612 if (TupleDescAttr(tupdesc, i)->attisdropped)
2613 continue;
2614
2615 if (!first)
2617 first = false;
2618
2619 /* Use attribute name or column_name option. */
2620 colname = NameStr(TupleDescAttr(tupdesc, i)->attname);
2621 options = GetForeignColumnOptions(relid, i + 1);
2622
2623 foreach(lc, options)
2624 {
2625 DefElem *def = (DefElem *) lfirst(lc);
2626
2627 if (strcmp(def->defname, "column_name") == 0)
2628 {
2629 colname = defGetString(def);
2630 break;
2631 }
2632 }
2633
2635
2636 *retrieved_attrs = lappend_int(*retrieved_attrs, i + 1);
2637 }
2638
2639 /* Don't generate bad syntax for zero-column relation. */
2640 if (first)
2641 appendStringInfoString(buf, "NULL");
2642
2643 /*
2644 * Construct FROM clause, and perhaps WHERE clause too, depending on the
2645 * selected sampling method.
2646 */
2647 appendStringInfoString(buf, " FROM ");
2648 deparseRelation(buf, rel);
2649
2650 switch (sample_method)
2651 {
2652 case ANALYZE_SAMPLE_OFF:
2653 /* nothing to do here */
2654 break;
2655
2657 appendStringInfo(buf, " WHERE pg_catalog.random() < %f", sample_frac);
2658 break;
2659
2661 appendStringInfo(buf, " TABLESAMPLE SYSTEM(%f)", (100.0 * sample_frac));
2662 break;
2663
2665 appendStringInfo(buf, " TABLESAMPLE BERNOULLI(%f)", (100.0 * sample_frac));
2666 break;
2667
2669 /* should have been resolved into actual method */
2670 elog(ERROR, "unexpected sampling method");
2671 break;
2672 }
2673}
2674
2675/*
2676 * Construct a simple "TRUNCATE rel" statement
2677 */
2678void
2680 List *rels,
2681 DropBehavior behavior,
2682 bool restart_seqs)
2683{
2684 ListCell *cell;
2685
2686 appendStringInfoString(buf, "TRUNCATE ");
2687
2688 foreach(cell, rels)
2689 {
2690 Relation rel = lfirst(cell);
2691
2692 if (cell != list_head(rels))
2694
2695 deparseRelation(buf, rel);
2696 }
2697
2698 appendStringInfo(buf, " %s IDENTITY",
2699 restart_seqs ? "RESTART" : "CONTINUE");
2700
2701 if (behavior == DROP_RESTRICT)
2702 appendStringInfoString(buf, " RESTRICT");
2703 else if (behavior == DROP_CASCADE)
2704 appendStringInfoString(buf, " CASCADE");
2705}
2706
2707/*
2708 * Construct name to use for given column, and emit it into buf.
2709 * If it has a column_name FDW option, use that instead of attribute name.
2710 *
2711 * If qualify_col is true, qualify column name with the alias of relation.
2712 */
2713static void
2714deparseColumnRef(StringInfo buf, int varno, int varattno, RangeTblEntry *rte,
2715 bool qualify_col)
2716{
2717 /* We support fetching the remote side's CTID and OID. */
2718 if (varattno == SelfItemPointerAttributeNumber)
2719 {
2720 if (qualify_col)
2721 ADD_REL_QUALIFIER(buf, varno);
2722 appendStringInfoString(buf, "ctid");
2723 }
2724 else if (varattno < 0)
2725 {
2726 /*
2727 * All other system attributes are fetched as 0, except for table OID,
2728 * which is fetched as the local table OID. However, we must be
2729 * careful; the table could be beneath an outer join, in which case it
2730 * must go to NULL whenever the rest of the row does.
2731 */
2732 Oid fetchval = 0;
2733
2734 if (varattno == TableOidAttributeNumber)
2735 fetchval = rte->relid;
2736
2737 if (qualify_col)
2738 {
2739 appendStringInfoString(buf, "CASE WHEN (");
2740 ADD_REL_QUALIFIER(buf, varno);
2741 appendStringInfo(buf, "*)::text IS NOT NULL THEN %u END", fetchval);
2742 }
2743 else
2744 appendStringInfo(buf, "%u", fetchval);
2745 }
2746 else if (varattno == 0)
2747 {
2748 /* Whole row reference */
2749 Relation rel;
2750 Bitmapset *attrs_used;
2751
2752 /* Required only to be passed down to deparseTargetList(). */
2753 List *retrieved_attrs;
2754
2755 /*
2756 * The lock on the relation will be held by upper callers, so it's
2757 * fine to open it with no lock here.
2758 */
2759 rel = table_open(rte->relid, NoLock);
2760
2761 /*
2762 * The local name of the foreign table can not be recognized by the
2763 * foreign server and the table it references on foreign server might
2764 * have different column ordering or different columns than those
2765 * declared locally. Hence we have to deparse whole-row reference as
2766 * ROW(columns referenced locally). Construct this by deparsing a
2767 * "whole row" attribute.
2768 */
2769 attrs_used = bms_add_member(NULL,
2771
2772 /*
2773 * In case the whole-row reference is under an outer join then it has
2774 * to go NULL whenever the rest of the row goes NULL. Deparsing a join
2775 * query would always involve multiple relations, thus qualify_col
2776 * would be true.
2777 */
2778 if (qualify_col)
2779 {
2780 appendStringInfoString(buf, "CASE WHEN (");
2781 ADD_REL_QUALIFIER(buf, varno);
2782 appendStringInfoString(buf, "*)::text IS NOT NULL THEN ");
2783 }
2784
2785 appendStringInfoString(buf, "ROW(");
2786 deparseTargetList(buf, rte, varno, rel, false, attrs_used, qualify_col,
2787 &retrieved_attrs);
2789
2790 /* Complete the CASE WHEN statement started above. */
2791 if (qualify_col)
2792 appendStringInfoString(buf, " END");
2793
2794 table_close(rel, NoLock);
2795 bms_free(attrs_used);
2796 }
2797 else
2798 {
2799 char *colname = NULL;
2800 List *options;
2801 ListCell *lc;
2802
2803 /* varno must not be any of OUTER_VAR, INNER_VAR and INDEX_VAR. */
2804 Assert(!IS_SPECIAL_VARNO(varno));
2805
2806 /*
2807 * If it's a column of a foreign table, and it has the column_name FDW
2808 * option, use that value.
2809 */
2810 options = GetForeignColumnOptions(rte->relid, varattno);
2811 foreach(lc, options)
2812 {
2813 DefElem *def = (DefElem *) lfirst(lc);
2814
2815 if (strcmp(def->defname, "column_name") == 0)
2816 {
2817 colname = defGetString(def);
2818 break;
2819 }
2820 }
2821
2822 /*
2823 * If it's a column of a regular table or it doesn't have column_name
2824 * FDW option, use attribute name.
2825 */
2826 if (colname == NULL)
2827 colname = get_attname(rte->relid, varattno, false);
2828
2829 if (qualify_col)
2830 ADD_REL_QUALIFIER(buf, varno);
2831
2833 }
2834}
2835
2836/*
2837 * Append remote name of specified foreign table to buf.
2838 * Use value of table_name FDW option (if any) instead of relation's name.
2839 * Similarly, schema_name FDW option overrides schema name.
2840 */
2841static void
2843{
2845 const char *nspname = NULL;
2846 const char *relname = NULL;
2847 ListCell *lc;
2848
2849 /* obtain additional catalog information. */
2851
2852 /*
2853 * Use value of FDW options if any, instead of the name of object itself.
2854 */
2855 foreach(lc, table->options)
2856 {
2857 DefElem *def = (DefElem *) lfirst(lc);
2858
2859 if (strcmp(def->defname, "schema_name") == 0)
2860 nspname = defGetString(def);
2861 else if (strcmp(def->defname, "table_name") == 0)
2862 relname = defGetString(def);
2863 }
2864
2865 /*
2866 * Note: we could skip printing the schema name if it's pg_catalog, but
2867 * that doesn't seem worth the trouble.
2868 */
2869 if (nspname == NULL)
2871 if (relname == NULL)
2873
2874 appendStringInfo(buf, "%s.%s",
2876}
2877
2878/*
2879 * Append a SQL string literal representing "val" to buf.
2880 */
2881void
2883{
2884 const char *valptr;
2885
2886 /*
2887 * Rather than making assumptions about the remote server's value of
2888 * standard_conforming_strings, always use E'foo' syntax if there are any
2889 * backslashes. This will fail on remote servers before 8.1, but those
2890 * are long out of support.
2891 */
2892 if (strchr(val, '\\') != NULL)
2895 for (valptr = val; *valptr; valptr++)
2896 {
2897 char ch = *valptr;
2898
2899 if (SQL_STR_DOUBLE(ch, true))
2902 }
2904}
2905
2906/*
2907 * Deparse given expression into context->buf.
2908 *
2909 * This function must support all the same node types that foreign_expr_walker
2910 * accepts.
2911 *
2912 * Note: unlike ruleutils.c, we just use a simple hard-wired parenthesization
2913 * scheme: anything more complex than a Var, Const, function call or cast
2914 * should be self-parenthesized.
2915 */
2916static void
2918{
2919 if (node == NULL)
2920 return;
2921
2922 switch (nodeTag(node))
2923 {
2924 case T_Var:
2925 deparseVar((Var *) node, context);
2926 break;
2927 case T_Const:
2928 deparseConst((Const *) node, context, 0);
2929 break;
2930 case T_Param:
2931 deparseParam((Param *) node, context);
2932 break;
2933 case T_SubscriptingRef:
2934 deparseSubscriptingRef((SubscriptingRef *) node, context);
2935 break;
2936 case T_FuncExpr:
2937 deparseFuncExpr((FuncExpr *) node, context);
2938 break;
2939 case T_OpExpr:
2940 deparseOpExpr((OpExpr *) node, context);
2941 break;
2942 case T_DistinctExpr:
2943 deparseDistinctExpr((DistinctExpr *) node, context);
2944 break;
2945 case T_ScalarArrayOpExpr:
2947 break;
2948 case T_RelabelType:
2949 deparseRelabelType((RelabelType *) node, context);
2950 break;
2951 case T_ArrayCoerceExpr:
2952 deparseArrayCoerceExpr((ArrayCoerceExpr *) node, context);
2953 break;
2954 case T_BoolExpr:
2955 deparseBoolExpr((BoolExpr *) node, context);
2956 break;
2957 case T_NullTest:
2958 deparseNullTest((NullTest *) node, context);
2959 break;
2960 case T_CaseExpr:
2961 deparseCaseExpr((CaseExpr *) node, context);
2962 break;
2963 case T_ArrayExpr:
2964 deparseArrayExpr((ArrayExpr *) node, context);
2965 break;
2966 case T_Aggref:
2967 deparseAggref((Aggref *) node, context);
2968 break;
2969 default:
2970 elog(ERROR, "unsupported expression type for deparse: %d",
2971 (int) nodeTag(node));
2972 break;
2973 }
2974}
2975
2976/*
2977 * Deparse given Var node into context->buf.
2978 *
2979 * If the Var belongs to the foreign relation, just print its remote name.
2980 * Otherwise, it's effectively a Param (and will in fact be a Param at
2981 * run time). Handle it the same way we handle plain Params --- see
2982 * deparseParam for comments.
2983 */
2984static void
2986{
2987 Relids relids = context->scanrel->relids;
2988 int relno;
2989 int colno;
2990
2991 /* Qualify columns when multiple relations are involved. */
2992 bool qualify_col = (bms_membership(relids) == BMS_MULTIPLE);
2993
2994 /*
2995 * If the Var belongs to the foreign relation that is deparsed as a
2996 * subquery, use the relation and column alias to the Var provided by the
2997 * subquery, instead of the remote name.
2998 */
2999 if (is_subquery_var(node, context->scanrel, &relno, &colno))
3000 {
3001 appendStringInfo(context->buf, "%s%d.%s%d",
3004 return;
3005 }
3006
3007 if (bms_is_member(node->varno, relids) && node->varlevelsup == 0)
3008 deparseColumnRef(context->buf, node->varno, node->varattno,
3009 planner_rt_fetch(node->varno, context->root),
3010 qualify_col);
3011 else
3012 {
3013 /* Treat like a Param */
3014 if (context->params_list)
3015 {
3016 int pindex = 0;
3017 ListCell *lc;
3018
3019 /* find its index in params_list */
3020 foreach(lc, *context->params_list)
3021 {
3022 pindex++;
3023 if (equal(node, (Node *) lfirst(lc)))
3024 break;
3025 }
3026 if (lc == NULL)
3027 {
3028 /* not in list, so add it */
3029 pindex++;
3030 *context->params_list = lappend(*context->params_list, node);
3031 }
3032
3033 printRemoteParam(pindex, node->vartype, node->vartypmod, context);
3034 }
3035 else
3036 {
3037 printRemotePlaceholder(node->vartype, node->vartypmod, context);
3038 }
3039 }
3040}
3041
3042/*
3043 * Deparse given constant value into context->buf.
3044 *
3045 * This function has to be kept in sync with ruleutils.c's get_const_expr.
3046 *
3047 * As in that function, showtype can be -1 to never show "::typename"
3048 * decoration, +1 to always show it, or 0 to show it only if the constant
3049 * wouldn't be assumed to be the right type by default.
3050 *
3051 * In addition, this code allows showtype to be -2 to indicate that we should
3052 * not show "::typename" decoration if the constant is printed as an untyped
3053 * literal or NULL (while in other cases, behaving as for showtype == 0).
3054 */
3055static void
3056deparseConst(Const *node, deparse_expr_cxt *context, int showtype)
3057{
3058 StringInfo buf = context->buf;
3059 Oid typoutput;
3060 bool typIsVarlena;
3061 char *extval;
3062 bool isfloat = false;
3063 bool isstring = false;
3064 bool needlabel;
3065
3066 if (node->constisnull)
3067 {
3068 appendStringInfoString(buf, "NULL");
3069 if (showtype >= 0)
3070 appendStringInfo(buf, "::%s",
3072 node->consttypmod));
3073 return;
3074 }
3075
3077 &typoutput, &typIsVarlena);
3078 extval = OidOutputFunctionCall(typoutput, node->constvalue);
3079
3080 switch (node->consttype)
3081 {
3082 case INT2OID:
3083 case INT4OID:
3084 case INT8OID:
3085 case OIDOID:
3086 case FLOAT4OID:
3087 case FLOAT8OID:
3088 case NUMERICOID:
3089 {
3090 /*
3091 * No need to quote unless it's a special value such as 'NaN'.
3092 * See comments in get_const_expr().
3093 */
3094 if (strspn(extval, "0123456789+-eE.") == strlen(extval))
3095 {
3096 if (extval[0] == '+' || extval[0] == '-')
3097 appendStringInfo(buf, "(%s)", extval);
3098 else
3099 appendStringInfoString(buf, extval);
3100 if (strcspn(extval, "eE.") != strlen(extval))
3101 isfloat = true; /* it looks like a float */
3102 }
3103 else
3104 appendStringInfo(buf, "'%s'", extval);
3105 }
3106 break;
3107 case BITOID:
3108 case VARBITOID:
3109 appendStringInfo(buf, "B'%s'", extval);
3110 break;
3111 case BOOLOID:
3112 if (strcmp(extval, "t") == 0)
3113 appendStringInfoString(buf, "true");
3114 else
3115 appendStringInfoString(buf, "false");
3116 break;
3117 default:
3118 deparseStringLiteral(buf, extval);
3119 isstring = true;
3120 break;
3121 }
3122
3123 pfree(extval);
3124
3125 if (showtype == -1)
3126 return; /* never print type label */
3127
3128 /*
3129 * For showtype == 0, append ::typename unless the constant will be
3130 * implicitly typed as the right type when it is read in.
3131 *
3132 * XXX this code has to be kept in sync with the behavior of the parser,
3133 * especially make_const.
3134 */
3135 switch (node->consttype)
3136 {
3137 case BOOLOID:
3138 case INT4OID:
3139 case UNKNOWNOID:
3140 needlabel = false;
3141 break;
3142 case NUMERICOID:
3143 needlabel = !isfloat || (node->consttypmod >= 0);
3144 break;
3145 default:
3146 if (showtype == -2)
3147 {
3148 /* label unless we printed it as an untyped string */
3149 needlabel = !isstring;
3150 }
3151 else
3152 needlabel = true;
3153 break;
3154 }
3155 if (needlabel || showtype > 0)
3156 appendStringInfo(buf, "::%s",
3158 node->consttypmod));
3159}
3160
3161/*
3162 * Deparse given Param node.
3163 *
3164 * If we're generating the query "for real", add the Param to
3165 * context->params_list if it's not already present, and then use its index
3166 * in that list as the remote parameter number. During EXPLAIN, there's
3167 * no need to identify a parameter number.
3168 */
3169static void
3171{
3172 if (context->params_list)
3173 {
3174 int pindex = 0;
3175 ListCell *lc;
3176
3177 /* find its index in params_list */
3178 foreach(lc, *context->params_list)
3179 {
3180 pindex++;
3181 if (equal(node, (Node *) lfirst(lc)))
3182 break;
3183 }
3184 if (lc == NULL)
3185 {
3186 /* not in list, so add it */
3187 pindex++;
3188 *context->params_list = lappend(*context->params_list, node);
3189 }
3190
3191 printRemoteParam(pindex, node->paramtype, node->paramtypmod, context);
3192 }
3193 else
3194 {
3195 printRemotePlaceholder(node->paramtype, node->paramtypmod, context);
3196 }
3197}
3198
3199/*
3200 * Deparse a container subscript expression.
3201 */
3202static void
3204{
3205 StringInfo buf = context->buf;
3206 ListCell *lowlist_item;
3207 ListCell *uplist_item;
3208
3209 /* Always parenthesize the expression. */
3211
3212 /*
3213 * Deparse referenced array expression first. If that expression includes
3214 * a cast, we have to parenthesize to prevent the array subscript from
3215 * being taken as typename decoration. We can avoid that in the typical
3216 * case of subscripting a Var, but otherwise do it.
3217 */
3218 if (IsA(node->refexpr, Var))
3219 deparseExpr(node->refexpr, context);
3220 else
3221 {
3223 deparseExpr(node->refexpr, context);
3225 }
3226
3227 /* Deparse subscript expressions. */
3228 lowlist_item = list_head(node->reflowerindexpr); /* could be NULL */
3229 foreach(uplist_item, node->refupperindexpr)
3230 {
3232 if (lowlist_item)
3233 {
3234 deparseExpr(lfirst(lowlist_item), context);
3236 lowlist_item = lnext(node->reflowerindexpr, lowlist_item);
3237 }
3238 deparseExpr(lfirst(uplist_item), context);
3240 }
3241
3243}
3244
3245/*
3246 * Deparse a function call.
3247 */
3248static void
3250{
3251 StringInfo buf = context->buf;
3252 bool use_variadic;
3253 bool first;
3254 ListCell *arg;
3255
3256 /*
3257 * If the function call came from an implicit coercion, then just show the
3258 * first argument.
3259 */
3260 if (node->funcformat == COERCE_IMPLICIT_CAST)
3261 {
3262 deparseExpr((Expr *) linitial(node->args), context);
3263 return;
3264 }
3265
3266 /*
3267 * If the function call came from a cast, then show the first argument
3268 * plus an explicit cast operation.
3269 */
3270 if (node->funcformat == COERCE_EXPLICIT_CAST)
3271 {
3272 Oid rettype = node->funcresulttype;
3273 int32 coercedTypmod;
3274
3275 /* Get the typmod if this is a length-coercion function */
3276 (void) exprIsLengthCoercion((Node *) node, &coercedTypmod);
3277
3278 deparseExpr((Expr *) linitial(node->args), context);
3279 appendStringInfo(buf, "::%s",
3280 deparse_type_name(rettype, coercedTypmod));
3281 return;
3282 }
3283
3284 /* Check if need to print VARIADIC (cf. ruleutils.c) */
3285 use_variadic = node->funcvariadic;
3286
3287 /*
3288 * Normal function: display as proname(args).
3289 */
3290 appendFunctionName(node->funcid, context);
3292
3293 /* ... and all the arguments */
3294 first = true;
3295 foreach(arg, node->args)
3296 {
3297 if (!first)
3299 if (use_variadic && lnext(node->args, arg) == NULL)
3300 appendStringInfoString(buf, "VARIADIC ");
3301 deparseExpr((Expr *) lfirst(arg), context);
3302 first = false;
3303 }
3305}
3306
3307/*
3308 * Deparse given operator expression. To avoid problems around
3309 * priority of operations, we always parenthesize the arguments.
3310 */
3311static void
3313{
3314 StringInfo buf = context->buf;
3315 HeapTuple tuple;
3316 Form_pg_operator form;
3317 Expr *right;
3318 bool canSuppressRightConstCast = false;
3319 char oprkind;
3320
3321 /* Retrieve information about the operator from system catalog. */
3322 tuple = SearchSysCache1(OPEROID, ObjectIdGetDatum(node->opno));
3323 if (!HeapTupleIsValid(tuple))
3324 elog(ERROR, "cache lookup failed for operator %u", node->opno);
3325 form = (Form_pg_operator) GETSTRUCT(tuple);
3326 oprkind = form->oprkind;
3327
3328 /* Sanity check. */
3329 Assert((oprkind == 'l' && list_length(node->args) == 1) ||
3330 (oprkind == 'b' && list_length(node->args) == 2));
3331
3332 right = llast(node->args);
3333
3334 /* Always parenthesize the expression. */
3336
3337 /* Deparse left operand, if any. */
3338 if (oprkind == 'b')
3339 {
3340 Expr *left = linitial(node->args);
3341 Oid leftType = exprType((Node *) left);
3342 Oid rightType = exprType((Node *) right);
3343 bool canSuppressLeftConstCast = false;
3344
3345 /*
3346 * When considering a binary operator, if one operand is a Const that
3347 * can be printed as a bare string literal or NULL (i.e., it will look
3348 * like type UNKNOWN to the remote parser), the Const normally
3349 * receives an explicit cast to the operator's input type. However,
3350 * in Const-to-Var comparisons where both operands are of the same
3351 * type, we prefer to suppress the explicit cast, leaving the Const's
3352 * type resolution up to the remote parser. The remote's resolution
3353 * heuristic will assume that an unknown input type being compared to
3354 * a known input type is of that known type as well.
3355 *
3356 * This hack allows some cases to succeed where a remote column is
3357 * declared with a different type in the local (foreign) table. By
3358 * emitting "foreigncol = 'foo'" not "foreigncol = 'foo'::text" or the
3359 * like, we allow the remote parser to pick an "=" operator that's
3360 * compatible with whatever type the remote column really is, such as
3361 * an enum.
3362 *
3363 * We allow cast suppression to happen only when the other operand is
3364 * a plain foreign Var. Although the remote's unknown-type heuristic
3365 * would apply to other cases just as well, we would be taking a
3366 * bigger risk that the inferred type is something unexpected. With
3367 * this restriction, if anything goes wrong it's the user's fault for
3368 * not declaring the local column with the same type as the remote
3369 * column.
3370 */
3371 if (leftType == rightType)
3372 {
3373 if (IsA(left, Const))
3374 canSuppressLeftConstCast = isPlainForeignVar(right, context);
3375 else if (IsA(right, Const))
3376 canSuppressRightConstCast = isPlainForeignVar(left, context);
3377 }
3378
3379 if (canSuppressLeftConstCast)
3380 deparseConst((Const *) left, context, -2);
3381 else
3382 deparseExpr(left, context);
3383
3385 }
3386
3387 /* Deparse operator name. */
3388 deparseOperatorName(buf, form);
3389
3390 /* Deparse right operand. */
3392
3393 if (canSuppressRightConstCast)
3394 deparseConst((Const *) right, context, -2);
3395 else
3396 deparseExpr(right, context);
3397
3399
3400 ReleaseSysCache(tuple);
3401}
3402
3403/*
3404 * Will "node" deparse as a plain foreign Var?
3405 */
3406static bool
3408{
3409 /*
3410 * We allow the foreign Var to have an implicit RelabelType, mainly so
3411 * that this'll work with varchar columns. Note that deparseRelabelType
3412 * will not print such a cast, so we're not breaking the restriction that
3413 * the expression print as a plain Var. We won't risk it for an implicit
3414 * cast that requires a function, nor for non-implicit RelabelType; such
3415 * cases seem too likely to involve semantics changes compared to what
3416 * would happen on the remote side.
3417 */
3418 if (IsA(node, RelabelType) &&
3419 ((RelabelType *) node)->relabelformat == COERCE_IMPLICIT_CAST)
3420 node = ((RelabelType *) node)->arg;
3421
3422 if (IsA(node, Var))
3423 {
3424 /*
3425 * The Var must be one that'll deparse as a foreign column reference
3426 * (cf. deparseVar).
3427 */
3428 Var *var = (Var *) node;
3429 Relids relids = context->scanrel->relids;
3430
3431 if (bms_is_member(var->varno, relids) && var->varlevelsup == 0)
3432 return true;
3433 }
3434
3435 return false;
3436}
3437
3438/*
3439 * Print the name of an operator.
3440 */
3441static void
3443{
3444 char *opname;
3445
3446 /* opname is not a SQL identifier, so we should not quote it. */
3447 opname = NameStr(opform->oprname);
3448
3449 /* Print schema name only if it's not pg_catalog */
3450 if (opform->oprnamespace != PG_CATALOG_NAMESPACE)
3451 {
3452 const char *opnspname;
3453
3454 opnspname = get_namespace_name(opform->oprnamespace);
3455 /* Print fully qualified operator name. */
3456 appendStringInfo(buf, "OPERATOR(%s.%s)",
3457 quote_identifier(opnspname), opname);
3458 }
3459 else
3460 {
3461 /* Just print operator name. */
3462 appendStringInfoString(buf, opname);
3463 }
3464}
3465
3466/*
3467 * Deparse IS DISTINCT FROM.
3468 */
3469static void
3471{
3472 StringInfo buf = context->buf;
3473
3474 Assert(list_length(node->args) == 2);
3475
3477 deparseExpr(linitial(node->args), context);
3478 appendStringInfoString(buf, " IS DISTINCT FROM ");
3479 deparseExpr(lsecond(node->args), context);
3481}
3482
3483/*
3484 * Deparse given ScalarArrayOpExpr expression. To avoid problems
3485 * around priority of operations, we always parenthesize the arguments.
3486 */
3487static void
3489{
3490 StringInfo buf = context->buf;
3491 HeapTuple tuple;
3492 Form_pg_operator form;
3493 Expr *arg1;
3494 Expr *arg2;
3495
3496 /* Retrieve information about the operator from system catalog. */
3497 tuple = SearchSysCache1(OPEROID, ObjectIdGetDatum(node->opno));
3498 if (!HeapTupleIsValid(tuple))
3499 elog(ERROR, "cache lookup failed for operator %u", node->opno);
3500 form = (Form_pg_operator) GETSTRUCT(tuple);
3501
3502 /* Sanity check. */
3503 Assert(list_length(node->args) == 2);
3504
3505 /* Always parenthesize the expression. */
3507
3508 /* Deparse left operand. */
3509 arg1 = linitial(node->args);
3510 deparseExpr(arg1, context);
3512
3513 /* Deparse operator name plus decoration. */
3514 deparseOperatorName(buf, form);
3515 appendStringInfo(buf, " %s (", node->useOr ? "ANY" : "ALL");
3516
3517 /* Deparse right operand. */
3518 arg2 = lsecond(node->args);
3519 deparseExpr(arg2, context);
3520
3522
3523 /* Always parenthesize the expression. */
3525
3526 ReleaseSysCache(tuple);
3527}
3528
3529/*
3530 * Deparse a RelabelType (binary-compatible cast) node.
3531 */
3532static void
3534{
3535 deparseExpr(node->arg, context);
3536 if (node->relabelformat != COERCE_IMPLICIT_CAST)
3537 appendStringInfo(context->buf, "::%s",
3539 node->resulttypmod));
3540}
3541
3542/*
3543 * Deparse an ArrayCoerceExpr (array-type conversion) node.
3544 */
3545static void
3547{
3548 deparseExpr(node->arg, context);
3549
3550 /*
3551 * No difference how to deparse explicit cast, but if we omit implicit
3552 * cast in the query, it'll be more user-friendly
3553 */
3554 if (node->coerceformat != COERCE_IMPLICIT_CAST)
3555 appendStringInfo(context->buf, "::%s",
3557 node->resulttypmod));
3558}
3559
3560/*
3561 * Deparse a BoolExpr node.
3562 */
3563static void
3565{
3566 StringInfo buf = context->buf;
3567 const char *op = NULL; /* keep compiler quiet */
3568 bool first;
3569 ListCell *lc;
3570
3571 switch (node->boolop)
3572 {
3573 case AND_EXPR:
3574 op = "AND";
3575 break;
3576 case OR_EXPR:
3577 op = "OR";
3578 break;
3579 case NOT_EXPR:
3580 appendStringInfoString(buf, "(NOT ");
3581 deparseExpr(linitial(node->args), context);
3583 return;
3584 }
3585
3587 first = true;
3588 foreach(lc, node->args)
3589 {
3590 if (!first)
3591 appendStringInfo(buf, " %s ", op);
3592 deparseExpr((Expr *) lfirst(lc), context);
3593 first = false;
3594 }
3596}
3597
3598/*
3599 * Deparse IS [NOT] NULL expression.
3600 */
3601static void
3603{
3604 StringInfo buf = context->buf;
3605
3607 deparseExpr(node->arg, context);
3608
3609 /*
3610 * For scalar inputs, we prefer to print as IS [NOT] NULL, which is
3611 * shorter and traditional. If it's a rowtype input but we're applying a
3612 * scalar test, must print IS [NOT] DISTINCT FROM NULL to be semantically
3613 * correct.
3614 */
3615 if (node->argisrow || !type_is_rowtype(exprType((Node *) node->arg)))
3616 {
3617 if (node->nulltesttype == IS_NULL)
3618 appendStringInfoString(buf, " IS NULL)");
3619 else
3620 appendStringInfoString(buf, " IS NOT NULL)");
3621 }
3622 else
3623 {
3624 if (node->nulltesttype == IS_NULL)
3625 appendStringInfoString(buf, " IS NOT DISTINCT FROM NULL)");
3626 else
3627 appendStringInfoString(buf, " IS DISTINCT FROM NULL)");
3628 }
3629}
3630
3631/*
3632 * Deparse CASE expression
3633 */
3634static void
3636{
3637 StringInfo buf = context->buf;
3638 ListCell *lc;
3639
3640 appendStringInfoString(buf, "(CASE");
3641
3642 /* If this is a CASE arg WHEN then emit the arg expression */
3643 if (node->arg != NULL)
3644 {
3646 deparseExpr(node->arg, context);
3647 }
3648
3649 /* Add each condition/result of the CASE clause */
3650 foreach(lc, node->args)
3651 {
3652 CaseWhen *whenclause = (CaseWhen *) lfirst(lc);
3653
3654 /* WHEN */
3655 appendStringInfoString(buf, " WHEN ");
3656 if (node->arg == NULL) /* CASE WHEN */
3657 deparseExpr(whenclause->expr, context);
3658 else /* CASE arg WHEN */
3659 {
3660 /* Ignore the CaseTestExpr and equality operator. */
3661 deparseExpr(lsecond(castNode(OpExpr, whenclause->expr)->args),
3662 context);
3663 }
3664
3665 /* THEN */
3666 appendStringInfoString(buf, " THEN ");
3667 deparseExpr(whenclause->result, context);
3668 }
3669
3670 /* add ELSE if present */
3671 if (node->defresult != NULL)
3672 {
3673 appendStringInfoString(buf, " ELSE ");
3674 deparseExpr(node->defresult, context);
3675 }
3676
3677 /* append END */
3678 appendStringInfoString(buf, " END)");
3679}
3680
3681/*
3682 * Deparse ARRAY[...] construct.
3683 */
3684static void
3686{
3687 StringInfo buf = context->buf;
3688 bool first = true;
3689 ListCell *lc;
3690
3691 appendStringInfoString(buf, "ARRAY[");
3692 foreach(lc, node->elements)
3693 {
3694 if (!first)
3696 deparseExpr(lfirst(lc), context);
3697 first = false;
3698 }
3700
3701 /* If the array is empty, we need an explicit cast to the array type. */
3702 if (node->elements == NIL)
3703 appendStringInfo(buf, "::%s",
3704 deparse_type_name(node->array_typeid, -1));
3705}
3706
3707/*
3708 * Deparse an Aggref node.
3709 */
3710static void
3712{
3713 StringInfo buf = context->buf;
3714 bool use_variadic;
3715
3716 /* Only basic, non-split aggregation accepted. */
3717 Assert(node->aggsplit == AGGSPLIT_SIMPLE);
3718
3719 /* Check if need to print VARIADIC (cf. ruleutils.c) */
3720 use_variadic = node->aggvariadic;
3721
3722 /* Find aggregate name from aggfnoid which is a pg_proc entry */
3723 appendFunctionName(node->aggfnoid, context);
3725
3726 /* Add DISTINCT */
3727 appendStringInfoString(buf, (node->aggdistinct != NIL) ? "DISTINCT " : "");
3728
3729 if (AGGKIND_IS_ORDERED_SET(node->aggkind))
3730 {
3731 /* Add WITHIN GROUP (ORDER BY ..) */
3732 ListCell *arg;
3733 bool first = true;
3734
3735 Assert(!node->aggvariadic);
3736 Assert(node->aggorder != NIL);
3737
3738 foreach(arg, node->aggdirectargs)
3739 {
3740 if (!first)
3742 first = false;
3743
3744 deparseExpr((Expr *) lfirst(arg), context);
3745 }
3746
3747 appendStringInfoString(buf, ") WITHIN GROUP (ORDER BY ");
3748 appendAggOrderBy(node->aggorder, node->args, context);
3749 }
3750 else
3751 {
3752 /* aggstar can be set only in zero-argument aggregates */
3753 if (node->aggstar)
3755 else
3756 {
3757 ListCell *arg;
3758 bool first = true;
3759
3760 /* Add all the arguments */
3761 foreach(arg, node->args)
3762 {
3763 TargetEntry *tle = (TargetEntry *) lfirst(arg);
3764 Node *n = (Node *) tle->expr;
3765
3766 if (tle->resjunk)
3767 continue;
3768
3769 if (!first)
3771 first = false;
3772
3773 /* Add VARIADIC */
3774 if (use_variadic && lnext(node->args, arg) == NULL)
3775 appendStringInfoString(buf, "VARIADIC ");
3776
3777 deparseExpr((Expr *) n, context);
3778 }
3779 }
3780
3781 /* Add ORDER BY */
3782 if (node->aggorder != NIL)
3783 {
3784 appendStringInfoString(buf, " ORDER BY ");
3785 appendAggOrderBy(node->aggorder, node->args, context);
3786 }
3787 }
3788
3789 /* Add FILTER (WHERE ..) */
3790 if (node->aggfilter != NULL)
3791 {
3792 appendStringInfoString(buf, ") FILTER (WHERE ");
3793 deparseExpr((Expr *) node->aggfilter, context);
3794 }
3795
3797}
3798
3799/*
3800 * Append ORDER BY within aggregate function.
3801 */
3802static void
3803appendAggOrderBy(List *orderList, List *targetList, deparse_expr_cxt *context)
3804{
3805 StringInfo buf = context->buf;
3806 ListCell *lc;
3807 bool first = true;
3808
3809 foreach(lc, orderList)
3810 {
3811 SortGroupClause *srt = (SortGroupClause *) lfirst(lc);
3812 Node *sortexpr;
3813
3814 if (!first)
3816 first = false;
3817
3818 /* Deparse the sort expression proper. */
3819 sortexpr = deparseSortGroupClause(srt->tleSortGroupRef, targetList,
3820 false, context);
3821 /* Add decoration as needed. */
3822 appendOrderBySuffix(srt->sortop, exprType(sortexpr), srt->nulls_first,
3823 context);
3824 }
3825}
3826
3827/*
3828 * Append the ASC, DESC, USING <OPERATOR> and NULLS FIRST / NULLS LAST parts
3829 * of an ORDER BY clause.
3830 */
3831static void
3832appendOrderBySuffix(Oid sortop, Oid sortcoltype, bool nulls_first,
3833 deparse_expr_cxt *context)
3834{
3835 StringInfo buf = context->buf;
3836 TypeCacheEntry *typentry;
3837
3838 /* See whether operator is default < or > for sort expr's datatype. */
3839 typentry = lookup_type_cache(sortcoltype,
3841
3842 if (sortop == typentry->lt_opr)
3843 appendStringInfoString(buf, " ASC");
3844 else if (sortop == typentry->gt_opr)
3845 appendStringInfoString(buf, " DESC");
3846 else
3847 {
3848 HeapTuple opertup;
3849 Form_pg_operator operform;
3850
3851 appendStringInfoString(buf, " USING ");
3852
3853 /* Append operator name. */
3854 opertup = SearchSysCache1(OPEROID, ObjectIdGetDatum(sortop));
3855 if (!HeapTupleIsValid(opertup))
3856 elog(ERROR, "cache lookup failed for operator %u", sortop);
3857 operform = (Form_pg_operator) GETSTRUCT(opertup);
3858 deparseOperatorName(buf, operform);
3859 ReleaseSysCache(opertup);
3860 }
3861
3862 if (nulls_first)
3863 appendStringInfoString(buf, " NULLS FIRST");
3864 else
3865 appendStringInfoString(buf, " NULLS LAST");
3866}
3867
3868/*
3869 * Print the representation of a parameter to be sent to the remote side.
3870 *
3871 * Note: we always label the Param's type explicitly rather than relying on
3872 * transmitting a numeric type OID in PQsendQueryParams(). This allows us to
3873 * avoid assuming that types have the same OIDs on the remote side as they
3874 * do locally --- they need only have the same names.
3875 */
3876static void
3877printRemoteParam(int paramindex, Oid paramtype, int32 paramtypmod,
3878 deparse_expr_cxt *context)
3879{
3880 StringInfo buf = context->buf;
3881 char *ptypename = deparse_type_name(paramtype, paramtypmod);
3882
3883 appendStringInfo(buf, "$%d::%s", paramindex, ptypename);
3884}
3885
3886/*
3887 * Print the representation of a placeholder for a parameter that will be
3888 * sent to the remote side at execution time.
3889 *
3890 * This is used when we're just trying to EXPLAIN the remote query.
3891 * We don't have the actual value of the runtime parameter yet, and we don't
3892 * want the remote planner to generate a plan that depends on such a value
3893 * anyway. Thus, we can't do something simple like "$1::paramtype".
3894 * Instead, we emit "((SELECT null::paramtype)::paramtype)".
3895 * In all extant versions of Postgres, the planner will see that as an unknown
3896 * constant value, which is what we want. This might need adjustment if we
3897 * ever make the planner flatten scalar subqueries. Note: the reason for the
3898 * apparently useless outer cast is to ensure that the representation as a
3899 * whole will be parsed as an a_expr and not a select_with_parens; the latter
3900 * would do the wrong thing in the context "x = ANY(...)".
3901 */
3902static void
3903printRemotePlaceholder(Oid paramtype, int32 paramtypmod,
3904 deparse_expr_cxt *context)
3905{
3906 StringInfo buf = context->buf;
3907 char *ptypename = deparse_type_name(paramtype, paramtypmod);
3908
3909 appendStringInfo(buf, "((SELECT null::%s)::%s)", ptypename, ptypename);
3910}
3911
3912/*
3913 * Deparse GROUP BY clause.
3914 */
3915static void
3917{
3918 StringInfo buf = context->buf;
3919 Query *query = context->root->parse;
3920 ListCell *lc;
3921 bool first = true;
3922
3923 /* Nothing to be done, if there's no GROUP BY clause in the query. */
3924 if (!query->groupClause)
3925 return;
3926
3927 appendStringInfoString(buf, " GROUP BY ");
3928
3929 /*
3930 * Queries with grouping sets are not pushed down, so we don't expect
3931 * grouping sets here.
3932 */
3933 Assert(!query->groupingSets);
3934
3935 /*
3936 * We intentionally print query->groupClause not processed_groupClause,
3937 * leaving it to the remote planner to get rid of any redundant GROUP BY
3938 * items again. This is necessary in case processed_groupClause reduced
3939 * to empty, and in any case the redundancy situation on the remote might
3940 * be different than what we think here.
3941 */
3942 foreach(lc, query->groupClause)
3943 {
3944 SortGroupClause *grp = (SortGroupClause *) lfirst(lc);
3945
3946 if (!first)
3948 first = false;
3949
3950 deparseSortGroupClause(grp->tleSortGroupRef, tlist, true, context);
3951 }
3952}
3953
3954/*
3955 * Deparse ORDER BY clause defined by the given pathkeys.
3956 *
3957 * The clause should use Vars from context->scanrel if !has_final_sort,
3958 * or from context->foreignrel's targetlist if has_final_sort.
3959 *
3960 * We find a suitable pathkey expression (some earlier step
3961 * should have verified that there is one) and deparse it.
3962 */
3963static void
3964appendOrderByClause(List *pathkeys, bool has_final_sort,
3965 deparse_expr_cxt *context)
3966{
3967 ListCell *lcell;
3968 int nestlevel;
3969 StringInfo buf = context->buf;
3970 bool gotone = false;
3971
3972 /* Make sure any constants in the exprs are printed portably */
3973 nestlevel = set_transmission_modes();
3974
3975 foreach(lcell, pathkeys)
3976 {
3977 PathKey *pathkey = lfirst(lcell);
3979 Expr *em_expr;
3980 Oid oprid;
3981
3982 if (has_final_sort)
3983 {
3984 /*
3985 * By construction, context->foreignrel is the input relation to
3986 * the final sort.
3987 */
3988 em = find_em_for_rel_target(context->root,
3989 pathkey->pk_eclass,
3990 context->foreignrel);
3991 }
3992 else
3993 em = find_em_for_rel(context->root,
3994 pathkey->pk_eclass,
3995 context->scanrel);
3996
3997 /*
3998 * We don't expect any error here; it would mean that shippability
3999 * wasn't verified earlier. For the same reason, we don't recheck
4000 * shippability of the sort operator.
4001 */
4002 if (em == NULL)
4003 elog(ERROR, "could not find pathkey item to sort");
4004
4005 em_expr = em->em_expr;
4006
4007 /*
4008 * If the member is a Const expression then we needn't add it to the
4009 * ORDER BY clause. This can happen in UNION ALL queries where the
4010 * union child targetlist has a Const. Adding these would be
4011 * wasteful, but also, for INT columns, an integer literal would be
4012 * seen as an ordinal column position rather than a value to sort by.
4013 * deparseConst() does have code to handle this, but it seems less
4014 * effort on all accounts just to skip these for ORDER BY clauses.
4015 */
4016 if (IsA(em_expr, Const))
4017 continue;
4018
4019 if (!gotone)
4020 {
4021 appendStringInfoString(buf, " ORDER BY ");
4022 gotone = true;
4023 }
4024 else
4026
4027 /*
4028 * Lookup the operator corresponding to the compare type in the
4029 * opclass. The datatype used by the opfamily is not necessarily the
4030 * same as the expression type (for array types for example).
4031 */
4033 em->em_datatype,
4034 em->em_datatype,
4035 pathkey->pk_cmptype);
4036 if (!OidIsValid(oprid))
4037 elog(ERROR, "missing operator %d(%u,%u) in opfamily %u",
4038 pathkey->pk_cmptype, em->em_datatype, em->em_datatype,
4039 pathkey->pk_opfamily);
4040
4041 deparseExpr(em_expr, context);
4042
4043 /*
4044 * Here we need to use the expression's actual type to discover
4045 * whether the desired operator will be the default or not.
4046 */
4047 appendOrderBySuffix(oprid, exprType((Node *) em_expr),
4048 pathkey->pk_nulls_first, context);
4049
4050 }
4051 reset_transmission_modes(nestlevel);
4052}
4053
4054/*
4055 * Deparse LIMIT/OFFSET clause.
4056 */
4057static void
4059{
4060 PlannerInfo *root = context->root;
4061 StringInfo buf = context->buf;
4062 int nestlevel;
4063
4064 /* Make sure any constants in the exprs are printed portably */
4065 nestlevel = set_transmission_modes();
4066
4067 if (root->parse->limitCount)
4068 {
4069 appendStringInfoString(buf, " LIMIT ");
4070 deparseExpr((Expr *) root->parse->limitCount, context);
4071 }
4072 if (root->parse->limitOffset)
4073 {
4074 appendStringInfoString(buf, " OFFSET ");
4075 deparseExpr((Expr *) root->parse->limitOffset, context);
4076 }
4077
4078 reset_transmission_modes(nestlevel);
4079}
4080
4081/*
4082 * appendFunctionName
4083 * Deparses function name from given function oid.
4084 */
4085static void
4087{
4088 StringInfo buf = context->buf;
4089 HeapTuple proctup;
4090 Form_pg_proc procform;
4091 const char *proname;
4092
4093 proctup = SearchSysCache1(PROCOID, ObjectIdGetDatum(funcid));
4094 if (!HeapTupleIsValid(proctup))
4095 elog(ERROR, "cache lookup failed for function %u", funcid);
4096 procform = (Form_pg_proc) GETSTRUCT(proctup);
4097
4098 /* Print schema name only if it's not pg_catalog */
4099 if (procform->pronamespace != PG_CATALOG_NAMESPACE)
4100 {
4101 const char *schemaname;
4102
4103 schemaname = get_namespace_name(procform->pronamespace);
4104 appendStringInfo(buf, "%s.", quote_identifier(schemaname));
4105 }
4106
4107 /* Always print the function name */
4108 proname = NameStr(procform->proname);
4110
4111 ReleaseSysCache(proctup);
4112}
4113
4114/*
4115 * Appends a sort or group clause.
4116 *
4117 * Like get_rule_sortgroupclause(), returns the expression tree, so caller
4118 * need not find it again.
4119 */
4120static Node *
4121deparseSortGroupClause(Index ref, List *tlist, bool force_colno,
4122 deparse_expr_cxt *context)
4123{
4124 StringInfo buf = context->buf;
4125 TargetEntry *tle;
4126 Expr *expr;
4127
4128 tle = get_sortgroupref_tle(ref, tlist);
4129 expr = tle->expr;
4130
4131 if (force_colno)
4132 {
4133 /* Use column-number form when requested by caller. */
4134 Assert(!tle->resjunk);
4135 appendStringInfo(buf, "%d", tle->resno);
4136 }
4137 else if (expr && IsA(expr, Const))
4138 {
4139 /*
4140 * Force a typecast here so that we don't emit something like "GROUP
4141 * BY 2", which will be misconstrued as a column position rather than
4142 * a constant.
4143 */
4144 deparseConst((Const *) expr, context, 1);
4145 }
4146 else if (!expr || IsA(expr, Var))
4147 deparseExpr(expr, context);
4148 else
4149 {
4150 /* Always parenthesize the expression. */
4152 deparseExpr(expr, context);
4154 }
4155
4156 return (Node *) expr;
4157}
4158
4159
4160/*
4161 * Returns true if given Var is deparsed as a subquery output column, in
4162 * which case, *relno and *colno are set to the IDs for the relation and
4163 * column alias to the Var provided by the subquery.
4164 */
4165static bool
4166is_subquery_var(Var *node, RelOptInfo *foreignrel, int *relno, int *colno)
4167{
4168 PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
4169 RelOptInfo *outerrel = fpinfo->outerrel;
4170 RelOptInfo *innerrel = fpinfo->innerrel;
4171
4172 /* Should only be called in these cases. */
4173 Assert(IS_SIMPLE_REL(foreignrel) || IS_JOIN_REL(foreignrel));
4174
4175 /*
4176 * If the given relation isn't a join relation, it doesn't have any lower
4177 * subqueries, so the Var isn't a subquery output column.
4178 */
4179 if (!IS_JOIN_REL(foreignrel))
4180 return false;
4181
4182 /*
4183 * If the Var doesn't belong to any lower subqueries, it isn't a subquery
4184 * output column.
4185 */
4186 if (!bms_is_member(node->varno, fpinfo->lower_subquery_rels))
4187 return false;
4188
4189 if (bms_is_member(node->varno, outerrel->relids))
4190 {
4191 /*
4192 * If outer relation is deparsed as a subquery, the Var is an output
4193 * column of the subquery; get the IDs for the relation/column alias.
4194 */
4195 if (fpinfo->make_outerrel_subquery)
4196 {
4197 get_relation_column_alias_ids(node, outerrel, relno, colno);
4198 return true;
4199 }
4200
4201 /* Otherwise, recurse into the outer relation. */
4202 return is_subquery_var(node, outerrel, relno, colno);
4203 }
4204 else
4205 {
4206 Assert(bms_is_member(node->varno, innerrel->relids));
4207
4208 /*
4209 * If inner relation is deparsed as a subquery, the Var is an output
4210 * column of the subquery; get the IDs for the relation/column alias.
4211 */
4212 if (fpinfo->make_innerrel_subquery)
4213 {
4214 get_relation_column_alias_ids(node, innerrel, relno, colno);
4215 return true;
4216 }
4217
4218 /* Otherwise, recurse into the inner relation. */
4219 return is_subquery_var(node, innerrel, relno, colno);
4220 }
4221}
4222
4223/*
4224 * Get the IDs for the relation and column alias to given Var belonging to
4225 * given relation, which are returned into *relno and *colno.
4226 */
4227static void
4229 int *relno, int *colno)
4230{
4231 PgFdwRelationInfo *fpinfo = (PgFdwRelationInfo *) foreignrel->fdw_private;
4232 int i;
4233 ListCell *lc;
4234
4235 /* Get the relation alias ID */
4236 *relno = fpinfo->relation_index;
4237
4238 /* Get the column alias ID */
4239 i = 1;
4240 foreach(lc, foreignrel->reltarget->exprs)
4241 {
4242 Var *tlvar = (Var *) lfirst(lc);
4243
4244 /*
4245 * Match reltarget entries only on varno/varattno. Ideally there
4246 * would be some cross-check on varnullingrels, but it's unclear what
4247 * to do exactly; we don't have enough context to know what that value
4248 * should be.
4249 */
4250 if (IsA(tlvar, Var) &&
4251 tlvar->varno == node->varno &&
4252 tlvar->varattno == node->varattno)
4253 {
4254 *colno = i;
4255 return;
4256 }
4257 i++;
4258 }
4259
4260 /* Shouldn't get here */
4261 elog(ERROR, "unexpected expression in subquery output");
4262}
int16 AttrNumber
Definition: attnum.h:21
Bitmapset * bms_make_singleton(int x)
Definition: bitmapset.c:216
int bms_next_member(const Bitmapset *a, int prevbit)
Definition: bitmapset.c:1306
void bms_free(Bitmapset *a)
Definition: bitmapset.c:239
bool bms_is_member(int x, const Bitmapset *a)
Definition: bitmapset.c:510
Bitmapset * bms_add_member(Bitmapset *a, int x)
Definition: bitmapset.c:815
BMS_Membership bms_membership(const Bitmapset *a)
Definition: bitmapset.c:781
@ BMS_MULTIPLE
Definition: bitmapset.h:73
#define FORMAT_TYPE_TYPEMOD_GIVEN
Definition: builtins.h:124
#define FORMAT_TYPE_FORCE_QUALIFY
Definition: builtins.h:126
#define NameStr(name)
Definition: c.h:752
uint16 bits16
Definition: c.h:547
#define ESCAPE_STRING_SYNTAX
Definition: c.h:1166
#define SQL_STR_DOUBLE(ch, escape_backslash)
Definition: c.h:1163
int32_t int32
Definition: c.h:535
unsigned int Index
Definition: c.h:620
#define OidIsValid(objectId)
Definition: c.h:775
bool contain_mutable_functions(Node *clause)
Definition: clauses.c:374
char * defGetString(DefElem *def)
Definition: define.c:35
static void deparseArrayCoerceExpr(ArrayCoerceExpr *node, deparse_expr_cxt *context)
Definition: deparse.c:3546
static void deparseRangeTblRef(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel, bool make_subquery, Index ignore_rel, List **ignore_conds, List **additional_conds, List **params_list)
Definition: deparse.c:2041
static void deparseCaseExpr(CaseExpr *node, deparse_expr_cxt *context)
Definition: deparse.c:3635
void deparseAnalyzeSizeSql(StringInfo buf, Relation rel)
Definition: deparse.c:2532
static void deparseBoolExpr(BoolExpr *node, deparse_expr_cxt *context)
Definition: deparse.c:3564
static void appendGroupByClause(List *tlist, deparse_expr_cxt *context)
Definition: deparse.c:3916
static void deparseTargetList(StringInfo buf, RangeTblEntry *rte, Index rtindex, Relation rel, bool is_returning, Bitmapset *attrs_used, bool qualify_col, List **retrieved_attrs)
Definition: deparse.c:1438
#define SUBQUERY_REL_ALIAS_PREFIX
Definition: deparse.c:113
static void deparseFromExpr(List *quals, deparse_expr_cxt *context)
Definition: deparse.c:1406
static Node * deparseSortGroupClause(Index ref, List *tlist, bool force_colno, deparse_expr_cxt *context)
Definition: deparse.c:4121
static void deparseLockingClause(deparse_expr_cxt *context)
Definition: deparse.c:1514
const char * get_jointype_name(JoinType jointype)
Definition: deparse.c:1674
void deparseAnalyzeInfoSql(StringInfo buf, Relation rel)
Definition: deparse.c:2554
static void deparseAggref(Aggref *node, deparse_expr_cxt *context)
Definition: deparse.c:3711
static void appendOrderBySuffix(Oid sortop, Oid sortcoltype, bool nulls_first, deparse_expr_cxt *context)
Definition: deparse.c:3832
void deparseDirectDeleteSql(StringInfo buf, PlannerInfo *root, Index rtindex, Relation rel, RelOptInfo *foreignrel, List *remote_conds, List **params_list, List *returningList, List **retrieved_attrs)
Definition: deparse.c:2424
#define REL_ALIAS_PREFIX
Definition: deparse.c:109
void deparseDirectUpdateSql(StringInfo buf, PlannerInfo *root, Index rtindex, Relation rel, RelOptInfo *foreignrel, List *targetlist, List *targetAttrs, List *remote_conds, List **params_list, List *returningList, List **retrieved_attrs)
Definition: deparse.c:2309
struct deparse_expr_cxt deparse_expr_cxt
static void get_relation_column_alias_ids(Var *node, RelOptInfo *foreignrel, int *relno, int *colno)
Definition: deparse.c:4228
FDWCollateState
Definition: deparse.c:80
@ FDW_COLLATE_SAFE
Definition: deparse.c:84
@ FDW_COLLATE_UNSAFE
Definition: deparse.c:85
@ FDW_COLLATE_NONE
Definition: deparse.c:81
static void printRemoteParam(int paramindex, Oid paramtype, int32 paramtypmod, deparse_expr_cxt *context)
Definition: deparse.c:3877
static bool is_subquery_var(Var *node, RelOptInfo *foreignrel, int *relno, int *colno)
Definition: deparse.c:4166
bool is_foreign_param(PlannerInfo *root, RelOptInfo *baserel, Expr *expr)
Definition: deparse.c:1115
static void printRemotePlaceholder(Oid paramtype, int32 paramtypmod, deparse_expr_cxt *context)
Definition: deparse.c:3903
static void appendOrderByClause(List *pathkeys, bool has_final_sort, deparse_expr_cxt *context)
Definition: deparse.c:3964
static bool foreign_expr_walker(Node *node, foreign_glob_cxt *glob_cxt, foreign_loc_cxt *outer_cxt, foreign_loc_cxt *case_arg_cxt)
Definition: deparse.c:312
static void deparseColumnRef(StringInfo buf, int varno, int varattno, RangeTblEntry *rte, bool qualify_col)
Definition: deparse.c:2714
static void deparseRelabelType(RelabelType *node, deparse_expr_cxt *context)
Definition: deparse.c:3533
static void deparseNullTest(NullTest *node, deparse_expr_cxt *context)
Definition: deparse.c:3602
static void deparseOperatorName(StringInfo buf, Form_pg_operator opform)
Definition: deparse.c:3442
static void deparseOpExpr(OpExpr *node, deparse_expr_cxt *context)
Definition: deparse.c:3312
static void deparseConst(Const *node, deparse_expr_cxt *context, int showtype)
Definition: deparse.c:3056
static bool isPlainForeignVar(Expr *node, deparse_expr_cxt *context)
Definition: deparse.c:3407
static void deparseDistinctExpr(DistinctExpr *node, deparse_expr_cxt *context)
Definition: deparse.c:3470
void deparseSelectStmtForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *rel, List *tlist, List *remote_conds, List *pathkeys, bool has_final_sort, bool has_limit, bool is_subquery, List **retrieved_attrs, List **params_list)
Definition: deparse.c:1266
static void deparseFuncExpr(FuncExpr *node, deparse_expr_cxt *context)
Definition: deparse.c:3249
void deparseStringLiteral(StringInfo buf, const char *val)
Definition: deparse.c:2882
void rebuildInsertSql(StringInfo buf, Relation rel, char *orig_query, List *target_attrs, int values_end_len, int num_params, int num_rows)
Definition: deparse.c:2189
struct foreign_glob_cxt foreign_glob_cxt
static void deparseArrayExpr(ArrayExpr *node, deparse_expr_cxt *context)
Definition: deparse.c:3685
void deparseInsertSql(StringInfo buf, RangeTblEntry *rte, Index rtindex, Relation rel, List *targetAttrs, bool doNothing, List *withCheckOptionList, List *returningList, List **retrieved_attrs, int *values_end_len)
Definition: deparse.c:2116
static void deparseReturningList(StringInfo buf, RangeTblEntry *rte, Index rtindex, Relation rel, bool trig_after_row, List *withCheckOptionList, List *returningList, List **retrieved_attrs)
Definition: deparse.c:2475
void deparseUpdateSql(StringInfo buf, RangeTblEntry *rte, Index rtindex, Relation rel, List *targetAttrs, List *withCheckOptionList, List *returningList, List **retrieved_attrs)
Definition: deparse.c:2249
static void deparseVar(Var *node, deparse_expr_cxt *context)
Definition: deparse.c:2985
static void appendFunctionName(Oid funcid, deparse_expr_cxt *context)
Definition: deparse.c:4086
static void appendConditions(List *exprs, deparse_expr_cxt *context)
Definition: deparse.c:1604
struct foreign_loc_cxt foreign_loc_cxt
void deparseDeleteSql(StringInfo buf, RangeTblEntry *rte, Index rtindex, Relation rel, List *returningList, List **retrieved_attrs)
Definition: deparse.c:2395
void deparseAnalyzeSql(StringInfo buf, Relation rel, PgFdwSamplingMethod sample_method, double sample_frac, List **retrieved_attrs)
Definition: deparse.c:2594
static void deparseSubscriptingRef(SubscriptingRef *node, deparse_expr_cxt *context)
Definition: deparse.c:3203
static void deparseRelation(StringInfo buf, Relation rel)
Definition: deparse.c:2842
static void deparseExplicitTargetList(List *tlist, bool is_returning, List **retrieved_attrs, deparse_expr_cxt *context)
Definition: deparse.c:1714
static char * deparse_type_name(Oid type_oid, int32 typemod)
Definition: deparse.c:1190
#define ADD_REL_QUALIFIER(buf, varno)
Definition: deparse.c:111
static void appendLimitClause(deparse_expr_cxt *context)
Definition: deparse.c:4058
static void deparseExpr(Expr *node, deparse_expr_cxt *context)
Definition: deparse.c:2917
bool is_foreign_expr(PlannerInfo *root, RelOptInfo *baserel, Expr *expr)
Definition: deparse.c:244
static void deparseFromExprForRel(StringInfo buf, PlannerInfo *root, RelOptInfo *foreignrel, bool use_alias, Index ignore_rel, List **ignore_conds, List **additional_conds, List **params_list)
Definition: deparse.c:1794
#define SUBQUERY_COL_ALIAS_PREFIX
Definition: deparse.c:114
void classifyConditions(PlannerInfo *root, RelOptInfo *baserel, List *input_conds, List **remote_conds, List **local_conds)
Definition: deparse.c:218
static void deparseScalarArrayOpExpr(ScalarArrayOpExpr *node, deparse_expr_cxt *context)
Definition: deparse.c:3488
static void appendWhereClause(List *exprs, List *additional_conds, deparse_expr_cxt *context)
Definition: deparse.c:1641
void deparseTruncateSql(StringInfo buf, List *rels, DropBehavior behavior, bool restart_seqs)
Definition: deparse.c:2679
static void deparseSubqueryTargetList(deparse_expr_cxt *context)
Definition: deparse.c:1750
bool is_foreign_pathkey(PlannerInfo *root, RelOptInfo *baserel, PathKey *pathkey)
Definition: deparse.c:1156
static void deparseSelectSql(List *tlist, bool is_subquery, List **retrieved_attrs, deparse_expr_cxt *context)
Definition: deparse.c:1348
static void deparseParam(Param *node, deparse_expr_cxt *context)
Definition: deparse.c:3170
List * build_tlist_to_deparse(RelOptInfo *foreignrel)
Definition: deparse.c:1209
static void appendAggOrderBy(List *orderList, List *targetList, deparse_expr_cxt *context)
Definition: deparse.c:3803
#define ERROR
Definition: elog.h:39
#define elog(elevel,...)
Definition: elog.h:226
bool equal(const void *a, const void *b)
Definition: equalfuncs.c:223
char * OidOutputFunctionCall(Oid functionId, Datum val)
Definition: fmgr.c:1762
ForeignTable * GetForeignTable(Oid relid)
Definition: foreign.c:255
List * GetForeignColumnOptions(Oid relid, AttrNumber attnum)
Definition: foreign.c:293
char * format_type_extended(Oid type_oid, int32 typemod, bits16 flags)
Definition: format_type.c:112
Assert(PointerIsAligned(start, uint64))
const char * str
#define HeapTupleIsValid(tuple)
Definition: htup.h:78
static void * GETSTRUCT(const HeapTupleData *tuple)
Definition: htup_details.h:728
long val
Definition: informix.c:689
int b
Definition: isn.c:74
int a
Definition: isn.c:73
int i
Definition: isn.c:77
if(TABLE==NULL||TABLE_index==NULL)
Definition: isn.c:81
List * lappend(List *list, void *datum)
Definition: list.c:339
List * list_concat(List *list1, const List *list2)
Definition: list.c:561
List * lappend_int(List *list, int datum)
Definition: list.c:357
void list_free(List *list)
Definition: list.c:1546
void list_free_deep(List *list)
Definition: list.c:1560
#define NoLock
Definition: lockdefs.h:34
@ LCS_FORUPDATE
Definition: lockoptions.h:27
@ LCS_NONE
Definition: lockoptions.h:23
@ LCS_FORSHARE
Definition: lockoptions.h:25
@ LCS_FORKEYSHARE
Definition: lockoptions.h:24
@ LCS_FORNOKEYUPDATE
Definition: lockoptions.h:26
bool type_is_rowtype(Oid typid)
Definition: lsyscache.c:2822
Oid get_opfamily_member_for_cmptype(Oid opfamily, Oid lefttype, Oid righttype, CompareType cmptype)
Definition: lsyscache.c:197
void getTypeOutputInfo(Oid type, Oid *typOutput, bool *typIsVarlena)
Definition: lsyscache.c:3074
char * get_attname(Oid relid, AttrNumber attnum, bool missing_ok)
Definition: lsyscache.c:920
char * get_namespace_name(Oid nspid)
Definition: lsyscache.c:3533
void pfree(void *pointer)
Definition: mcxt.c:1594
Oid exprType(const Node *expr)
Definition: nodeFuncs.c:42
bool exprIsLengthCoercion(const Node *expr, int32 *coercedTypmod)
Definition: nodeFuncs.c:557
Node * strip_implicit_coercions(Node *node)
Definition: nodeFuncs.c:705
#define IsA(nodeptr, _type_)
Definition: nodes.h:164
#define nodeTag(nodeptr)
Definition: nodes.h:139
@ CMD_DELETE
Definition: nodes.h:278
@ CMD_UPDATE
Definition: nodes.h:276
@ AGGSPLIT_SIMPLE
Definition: nodes.h:387
#define castNode(_type_, nodeptr)
Definition: nodes.h:182
JoinType
Definition: nodes.h:298
@ JOIN_SEMI
Definition: nodes.h:317
@ JOIN_FULL
Definition: nodes.h:305
@ JOIN_INNER
Definition: nodes.h:303
@ JOIN_RIGHT
Definition: nodes.h:306
@ JOIN_LEFT
Definition: nodes.h:304
#define PVC_RECURSE_PLACEHOLDERS
Definition: optimizer.h:188
Oid oprid(Operator op)
Definition: parse_oper.c:239
DropBehavior
Definition: parsenodes.h:2394
@ DROP_CASCADE
Definition: parsenodes.h:2396
@ DROP_RESTRICT
Definition: parsenodes.h:2395
#define IS_SIMPLE_REL(rel)
Definition: pathnodes.h:876
#define IS_JOIN_REL(rel)
Definition: pathnodes.h:881
#define planner_rt_fetch(rti, root)
Definition: pathnodes.h:591
@ RELOPT_JOINREL
Definition: pathnodes.h:865
#define IS_UPPER_REL(rel)
Definition: pathnodes.h:886
NameData attname
Definition: pg_attribute.h:41
int16 attnum
Definition: pg_attribute.h:74
FormData_pg_attribute * Form_pg_attribute
Definition: pg_attribute.h:202
void * arg
NameData relname
Definition: pg_class.h:38
while(p+4<=pend)
#define lfirst(lc)
Definition: pg_list.h:172
#define llast(l)
Definition: pg_list.h:198
#define lfirst_node(type, lc)
Definition: pg_list.h:176
static int list_length(const List *l)
Definition: pg_list.h:152
#define NIL
Definition: pg_list.h:68
#define forboth(cell1, list1, cell2, list2)
Definition: pg_list.h:518
#define lfirst_int(lc)
Definition: pg_list.h:173
#define linitial(l)
Definition: pg_list.h:178
#define lsecond(l)
Definition: pg_list.h:183
static ListCell * list_head(const List *l)
Definition: pg_list.h:128
static ListCell * lnext(const List *l, const ListCell *c)
Definition: pg_list.h:343
static const struct lconv_member_info table[]
FormData_pg_operator * Form_pg_operator
Definition: pg_operator.h:83
FormData_pg_proc * Form_pg_proc
Definition: pg_proc.h:136
NameData proname
Definition: pg_proc.h:35
static char ** options
static char * buf
Definition: pg_test_fsync.c:72
static Oid DatumGetObjectId(Datum X)
Definition: postgres.h:252
static Datum ObjectIdGetDatum(Oid X)
Definition: postgres.h:262
#define InvalidOid
Definition: postgres_ext.h:37
unsigned int Oid
Definition: postgres_ext.h:32
void reset_transmission_modes(int nestlevel)
int set_transmission_modes(void)
EquivalenceMember * find_em_for_rel_target(PlannerInfo *root, EquivalenceClass *ec, RelOptInfo *rel)
EquivalenceMember * find_em_for_rel(PlannerInfo *root, EquivalenceClass *ec, RelOptInfo *rel)
bool is_shippable(Oid objectId, Oid classId, PgFdwRelationInfo *fpinfo)
Definition: shippable.c:162
bool is_builtin(Oid objectId)
Definition: shippable.c:152
PgFdwSamplingMethod
Definition: postgres_fdw.h:146
@ ANALYZE_SAMPLE_AUTO
Definition: postgres_fdw.h:148
@ ANALYZE_SAMPLE_OFF
Definition: postgres_fdw.h:147
@ ANALYZE_SAMPLE_BERNOULLI
Definition: postgres_fdw.h:151
@ ANALYZE_SAMPLE_SYSTEM
Definition: postgres_fdw.h:150
@ ANALYZE_SAMPLE_RANDOM
Definition: postgres_fdw.h:149
char * c
e
Definition: preproc-init.c:82
static int fe(enum e x)
Definition: preproc-init.c:111
PlanRowMark * get_plan_rowmark(List *rowmarks, Index rtindex)
Definition: preptlist.c:526
@ AND_EXPR
Definition: primnodes.h:950
@ OR_EXPR
Definition: primnodes.h:950
@ NOT_EXPR
Definition: primnodes.h:950
@ PARAM_MULTIEXPR
Definition: primnodes.h:387
#define IS_SPECIAL_VARNO(varno)
Definition: primnodes.h:247
@ COERCE_IMPLICIT_CAST
Definition: primnodes.h:755
@ COERCE_EXPLICIT_CAST
Definition: primnodes.h:754
@ IS_NULL
Definition: primnodes.h:1963
tree ctl root
Definition: radixtree.h:1857
#define RelationGetRelid(relation)
Definition: rel.h:514
#define RelationGetDescr(relation)
Definition: rel.h:540
#define RelationGetRelationName(relation)
Definition: rel.h:548
#define RelationGetNamespace(relation)
Definition: rel.h:555
const char * quote_identifier(const char *ident)
Definition: ruleutils.c:13028
void appendStringInfo(StringInfo str, const char *fmt,...)
Definition: stringinfo.c:145
void appendBinaryStringInfo(StringInfo str, const void *data, int datalen)
Definition: stringinfo.c:281
void appendStringInfoString(StringInfo str, const char *s)
Definition: stringinfo.c:230
void appendStringInfoChar(StringInfo str, char ch)
Definition: stringinfo.c:242
void initStringInfo(StringInfo str)
Definition: stringinfo.c:97
Oid aggfnoid
Definition: primnodes.h:463
List * aggdistinct
Definition: primnodes.h:493
List * aggdirectargs
Definition: primnodes.h:484
List * args
Definition: primnodes.h:487
Expr * aggfilter
Definition: primnodes.h:496
List * aggorder
Definition: primnodes.h:490
BoolExprType boolop
Definition: primnodes.h:958
List * args
Definition: primnodes.h:959
Expr * arg
Definition: primnodes.h:1332
Expr * defresult
Definition: primnodes.h:1334
List * args
Definition: primnodes.h:1333
Expr * result
Definition: primnodes.h:1345
Expr * expr
Definition: primnodes.h:1344
Oid consttype
Definition: primnodes.h:329
char * defname
Definition: parsenodes.h:841
Oid funcid
Definition: primnodes.h:769
List * args
Definition: primnodes.h:787
Definition: pg_list.h:54
Definition: nodes.h:135
NullTestType nulltesttype
Definition: primnodes.h:1970
Expr * arg
Definition: primnodes.h:1969
Oid opno
Definition: primnodes.h:837
List * args
Definition: primnodes.h:855
int32 paramtypmod
Definition: primnodes.h:399
Oid paramtype
Definition: primnodes.h:397
ParamKind paramkind
Definition: primnodes.h:395
Oid paramcollid
Definition: primnodes.h:401
CompareType pk_cmptype
Definition: pathnodes.h:1628
bool pk_nulls_first
Definition: pathnodes.h:1629
Oid pk_opfamily
Definition: pathnodes.h:1627
List * exprs
Definition: pathnodes.h:1691
Relids lower_subquery_rels
Definition: postgres_fdw.h:120
RelOptInfo * outerrel
Definition: postgres_fdw.h:103
Bitmapset * attrs_used
Definition: postgres_fdw.h:50
RelOptInfo * innerrel
Definition: postgres_fdw.h:104
LockClauseStrength strength
Definition: plannodes.h:1593
Query * parse
Definition: pathnodes.h:220
List * groupClause
Definition: parsenodes.h:216
List * groupingSets
Definition: parsenodes.h:219
Relids relids
Definition: pathnodes.h:908
struct PathTarget * reltarget
Definition: pathnodes.h:930
Index relid
Definition: pathnodes.h:954
RelOptKind reloptkind
Definition: pathnodes.h:902
Oid resulttype
Definition: primnodes.h:1204
Expr * arg
Definition: primnodes.h:1203
TriggerDesc * trigdesc
Definition: rel.h:117
Expr * clause
Definition: pathnodes.h:2704
Index tleSortGroupRef
Definition: parsenodes.h:1467
Expr * refassgnexpr
Definition: primnodes.h:722
List * refupperindexpr
Definition: primnodes.h:712
Expr * refexpr
Definition: primnodes.h:720
List * reflowerindexpr
Definition: primnodes.h:718
Expr * expr
Definition: primnodes.h:2225
AttrNumber resno
Definition: primnodes.h:2227
bool trig_update_after_row
Definition: reltrigger.h:62
bool trig_insert_after_row
Definition: reltrigger.h:57
bool trig_delete_after_row
Definition: reltrigger.h:67
Definition: primnodes.h:262
AttrNumber varattno
Definition: primnodes.h:274
int varno
Definition: primnodes.h:269
Index varlevelsup
Definition: primnodes.h:294
PlannerInfo * root
Definition: deparse.c:100
List ** params_list
Definition: deparse.c:106
RelOptInfo * foreignrel
Definition: deparse.c:101
StringInfo buf
Definition: deparse.c:105
RelOptInfo * scanrel
Definition: deparse.c:102
RelOptInfo * foreignrel
Definition: deparse.c:70
Relids relids
Definition: deparse.c:71
PlannerInfo * root
Definition: deparse.c:69
FDWCollateState state
Definition: deparse.c:92
char data[NAMEDATALEN]
Definition: c.h:748
Definition: regguts.h:323
#define FirstLowInvalidHeapAttributeNumber
Definition: sysattr.h:27
#define TableOidAttributeNumber
Definition: sysattr.h:26
#define SelfItemPointerAttributeNumber
Definition: sysattr.h:21
void ReleaseSysCache(HeapTuple tuple)
Definition: syscache.c:264
HeapTuple SearchSysCache1(int cacheId, Datum key1)
Definition: syscache.c:220
void table_close(Relation relation, LOCKMODE lockmode)
Definition: table.c:126
Relation table_open(Oid relationId, LOCKMODE lockmode)
Definition: table.c:40
TargetEntry * get_sortgroupref_tle(Index sortref, List *targetList)
Definition: tlist.c:345
List * add_to_flat_tlist(List *tlist, List *exprs)
Definition: tlist.c:132
#define FirstNormalObjectId
Definition: transam.h:197
static FormData_pg_attribute * TupleDescAttr(TupleDesc tupdesc, int i)
Definition: tupdesc.h:160
TypeCacheEntry * lookup_type_cache(Oid type_id, int flags)
Definition: typcache.c:386
#define TYPECACHE_GT_OPR
Definition: typcache.h:140
#define TYPECACHE_LT_OPR
Definition: typcache.h:139
List * pull_var_clause(Node *node, int flags)
Definition: var.c:653
void pull_varattnos(Node *node, Index varno, Bitmapset **varattnos)
Definition: var.c:296