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Adjust indexscan planning logic to keep RestrictInfo nodes associated
with index qual clauses in the Path representation. This saves a little work during createplan and (probably more importantly) allows reuse of cached selectivity estimates during indexscan planning. Also fix latent bug: wrong plan would have been generated for a 'special operator' used in a nestloop-inner-indexscan join qual, because the special operator would not have gotten into the list of quals to recheck. This bug is only latent because at present the special-operator code could never trigger on a join qual, but sooner or later someone will want to do it.
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11 files changed

+400
-188
lines changed

11 files changed

+400
-188
lines changed

‎src/backend/nodes/outfuncs.c

Lines changed: 4 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $PostgreSQL: pgsql/src/backend/nodes/outfuncs.c,v 1.227 2004/01/05 18:04:38 tgl Exp $
11+
* $PostgreSQL: pgsql/src/backend/nodes/outfuncs.c,v 1.228 2004/01/05 23:39:53 tgl Exp $
1212
*
1313
* NOTES
1414
* Every node type that can appear in stored rules' parsetrees *must*
@@ -968,8 +968,9 @@ _outIndexPath(StringInfo str, IndexPath *node)
968968
_outPathInfo(str, (Path *) node);
969969

970970
WRITE_NODE_FIELD(indexinfo);
971-
WRITE_NODE_FIELD(indexqual);
972-
WRITE_NODE_FIELD(indexjoinclauses);
971+
WRITE_NODE_FIELD(indexclauses);
972+
WRITE_NODE_FIELD(indexquals);
973+
WRITE_BOOL_FIELD(isjoininner);
973974
WRITE_ENUM_FIELD(indexscandir, ScanDirection);
974975
WRITE_FLOAT_FIELD(rows, "%.0f");
975976
}

‎src/backend/optimizer/path/costsize.c

Lines changed: 4 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -49,7 +49,7 @@
4949
* Portions Copyright (c) 1994, Regents of the University of California
5050
*
5151
* IDENTIFICATION
52-
* $PostgreSQL: pgsql/src/backend/optimizer/path/costsize.c,v 1.120 2004/01/05 05:07:35 tgl Exp $
52+
* $PostgreSQL: pgsql/src/backend/optimizer/path/costsize.c,v 1.121 2004/01/05 23:39:54 tgl Exp $
5353
*
5454
*-------------------------------------------------------------------------
5555
*/
@@ -238,6 +238,9 @@ cost_nonsequential_access(double relpages)
238238
* Any additional quals evaluated as qpquals may reduce the number of returned
239239
* tuples, but they won't reduce the number of tuples we have to fetch from
240240
* the table, so they don't reduce the scan cost.
241+
*
242+
* NOTE: as of 7.5, indexQuals is a list of RestrictInfo nodes, where formerly
243+
* it was a list of bare clause expressions.
241244
*/
242245
void
243246
cost_index(Path *path, Query *root,

‎src/backend/optimizer/path/indxpath.c

Lines changed: 77 additions & 28 deletions
Original file line numberDiff line numberDiff line change
@@ -9,7 +9,7 @@
99
*
1010
*
1111
* IDENTIFICATION
12-
* $PostgreSQL: pgsql/src/backend/optimizer/path/indxpath.c,v 1.154 2004/01/05 05:07:35 tgl Exp $
12+
* $PostgreSQL: pgsql/src/backend/optimizer/path/indxpath.c,v 1.155 2004/01/05 23:39:54 tgl Exp $
1313
*
1414
*-------------------------------------------------------------------------
1515
*/
@@ -76,7 +76,7 @@ static bool match_index_to_operand(Node *operand, int indexcol,
7676
RelOptInfo *rel, IndexOptInfo *index);
7777
static bool match_special_index_operator(Expr *clause, Oid opclass,
7878
bool indexkey_on_left);
79-
static List *expand_indexqual_condition(Expr *clause, Oid opclass);
79+
static List *expand_indexqual_condition(RestrictInfo *rinfo, Oid opclass);
8080
static List *prefix_quals(Node *leftop, Oid opclass,
8181
Const *prefix, Pattern_Prefix_Status pstatus);
8282
static List *network_prefix_quals(Node *leftop, Oid expr_op, Oid opclass,
@@ -1418,8 +1418,7 @@ make_innerjoin_index_path(Query *root,
14181418
{
14191419
IndexPath *pathnode = makeNode(IndexPath);
14201420
List *indexquals,
1421-
*allclauses,
1422-
*l;
1421+
*allclauses;
14231422

14241423
/* XXX perhaps this code should be merged with create_index_path? */
14251424

@@ -1433,28 +1432,21 @@ make_innerjoin_index_path(Query *root,
14331432
*/
14341433
pathnode->path.pathkeys = NIL;
14351434

1436-
/* Convert RestrictInfo nodes to indexquals the executor can handle */
1435+
/* Convert clauses to indexquals the executor can handle */
14371436
indexquals = expand_indexqual_conditions(index, clausegroups);
14381437

1439-
/*
1440-
* Also make a flattened list of the RestrictInfo nodes; createplan.c
1441-
* will need this later. We assume here that we can destructively
1442-
* modify the passed-in clausegroups list structure.
1443-
*/
1444-
allclauses = NIL;
1445-
foreach(l, clausegroups)
1446-
{
1447-
/* nconc okay here since same clause couldn't be in two sublists */
1448-
allclauses = nconc(allclauses, (List *) lfirst(l));
1449-
}
1438+
/* Flatten the clausegroups list to produce indexclauses list */
1439+
allclauses = flatten_clausegroups_list(clausegroups);
14501440

14511441
/*
14521442
* Note that we are making a pathnode for a single-scan indexscan;
1453-
* therefore, indexinfo and indexqual should be single-element lists.
1443+
* therefore, indexinfo etc should be single-element lists.
14541444
*/
14551445
pathnode->indexinfo = makeList1(index);
1456-
pathnode->indexqual = makeList1(indexquals);
1457-
pathnode->indexjoinclauses = makeList1(allclauses);
1446+
pathnode->indexclauses = makeList1(allclauses);
1447+
pathnode->indexquals = makeList1(indexquals);
1448+
1449+
pathnode->isjoininner = true;
14581450

14591451
/* We don't actually care what order the index scans in ... */
14601452
pathnode->indexscandir = NoMovementScanDirection;
@@ -1489,6 +1481,61 @@ make_innerjoin_index_path(Query *root,
14891481
return (Path *) pathnode;
14901482
}
14911483

1484+
/*
1485+
* flatten_clausegroups_list
1486+
* Given a list of lists of RestrictInfos, flatten it to a list
1487+
* of RestrictInfos.
1488+
*
1489+
* This is used to flatten out the result of group_clauses_by_indexkey()
1490+
* or one of its sibling routines, to produce an indexclauses list.
1491+
*/
1492+
List *
1493+
flatten_clausegroups_list(List *clausegroups)
1494+
{
1495+
List *allclauses = NIL;
1496+
List *l;
1497+
1498+
foreach(l, clausegroups)
1499+
{
1500+
allclauses = nconc(allclauses, listCopy((List *) lfirst(l)));
1501+
}
1502+
return allclauses;
1503+
}
1504+
1505+
/*
1506+
* make_expr_from_indexclauses()
1507+
* Given an indexclauses structure, produce an ordinary boolean expression.
1508+
*
1509+
* This consists of stripping out the RestrictInfo nodes and inserting
1510+
* explicit AND and OR nodes as needed. There's not much to it, but
1511+
* the functionality is needed in a few places, so centralize the logic.
1512+
*/
1513+
Expr *
1514+
make_expr_from_indexclauses(List *indexclauses)
1515+
{
1516+
List *orclauses = NIL;
1517+
List *orlist;
1518+
1519+
/* There's no such thing as an indexpath with zero scans */
1520+
Assert(indexclauses != NIL);
1521+
1522+
foreach(orlist, indexclauses)
1523+
{
1524+
List *andlist = (List *) lfirst(orlist);
1525+
1526+
/* Strip RestrictInfos */
1527+
andlist = get_actual_clauses(andlist);
1528+
/* Insert AND node if needed, and add to orclauses list */
1529+
orclauses = lappend(orclauses, make_ands_explicit(andlist));
1530+
}
1531+
1532+
if (length(orclauses) > 1)
1533+
return make_orclause(orclauses);
1534+
else
1535+
return (Expr *) lfirst(orclauses);
1536+
}
1537+
1538+
14921539
/****************************************************************************
14931540
* ---- ROUTINES TO CHECK OPERANDS ----
14941541
****************************************************************************/
@@ -1799,8 +1846,7 @@ expand_indexqual_conditions(IndexOptInfo *index, List *clausegroups)
17991846
RestrictInfo *rinfo = (RestrictInfo *) lfirst(i);
18001847

18011848
FastConc(&resultquals,
1802-
expand_indexqual_condition(rinfo->clause,
1803-
curClass));
1849+
expand_indexqual_condition(rinfo, curClass));
18041850
}
18051851

18061852
clausegroups = lnext(clausegroups);
@@ -1816,10 +1862,13 @@ expand_indexqual_conditions(IndexOptInfo *index, List *clausegroups)
18161862

18171863
/*
18181864
* expand_indexqual_condition --- expand a single indexqual condition
1865+
*
1866+
* The input is a single RestrictInfo, the output a list of RestrictInfos
18191867
*/
18201868
static List *
1821-
expand_indexqual_condition(Expr *clause, Oid opclass)
1869+
expand_indexqual_condition(RestrictInfo *rinfo, Oid opclass)
18221870
{
1871+
Expr *clause = rinfo->clause;
18231872
/* we know these will succeed */
18241873
Node *leftop = get_leftop(clause);
18251874
Node *rightop = get_rightop(clause);
@@ -1883,7 +1932,7 @@ expand_indexqual_condition(Expr *clause, Oid opclass)
18831932
break;
18841933

18851934
default:
1886-
result = makeList1(clause);
1935+
result = makeList1(rinfo);
18871936
break;
18881937
}
18891938

@@ -1978,7 +2027,7 @@ prefix_quals(Node *leftop, Oid opclass,
19782027
elog(ERROR, "no = operator for opclass %u", opclass);
19792028
expr = make_opclause(oproid, BOOLOID, false,
19802029
(Expr *) leftop, (Expr *) prefix_const);
1981-
result = makeList1(expr);
2030+
result = makeList1(make_restrictinfo(expr, true, true));
19822031
return result;
19832032
}
19842033

@@ -1993,7 +2042,7 @@ prefix_quals(Node *leftop, Oid opclass,
19932042
elog(ERROR, "no >= operator for opclass %u", opclass);
19942043
expr = make_opclause(oproid, BOOLOID, false,
19952044
(Expr *) leftop, (Expr *) prefix_const);
1996-
result = makeList1(expr);
2045+
result = makeList1(make_restrictinfo(expr, true, true));
19972046

19982047
/*-------
19992048
* If we can create a string larger than the prefix, we can say
@@ -2009,7 +2058,7 @@ prefix_quals(Node *leftop, Oid opclass,
20092058
elog(ERROR, "no < operator for opclass %u", opclass);
20102059
expr = make_opclause(oproid, BOOLOID, false,
20112060
(Expr *) leftop, (Expr *) greaterstr);
2012-
result = lappend(result, expr);
2061+
result = lappend(result, make_restrictinfo(expr, true, true));
20132062
}
20142063

20152064
return result;
@@ -2080,7 +2129,7 @@ network_prefix_quals(Node *leftop, Oid expr_op, Oid opclass, Datum rightop)
20802129
(Expr *) leftop,
20812130
(Expr *) makeConst(datatype, -1, opr1right,
20822131
false, false));
2083-
result = makeList1(expr);
2132+
result = makeList1(make_restrictinfo(expr, true, true));
20842133

20852134
/* create clause "key <= network_scan_last( rightop )" */
20862135

@@ -2095,7 +2144,7 @@ network_prefix_quals(Node *leftop, Oid expr_op, Oid opclass, Datum rightop)
20952144
(Expr *) leftop,
20962145
(Expr *) makeConst(datatype, -1, opr2right,
20972146
false, false));
2098-
result = lappend(result, expr);
2147+
result = lappend(result, make_restrictinfo(expr, true, true));
20992148

21002149
return result;
21012150
}

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