Add comment about why BETWEEN uses operator strings and not opclasses,

bmomjian · bmomjian · commit ae3c07522100 · 2009-01-07T22:54:45.000Z
with URL pointing to email discussion.
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.651 2009/01/01 17:23:45 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.652 2009/01/07 22:54:45 momjian Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -8361,6 +8361,11 @@ a_expr:		c_expr									{ $$ = $1; }
 				{
 					$$ = (Node *) makeSimpleA_Expr(AEXPR_OF, "<>", $1, (Node *) $6, @2);
 				}
+			/*
+			 *	Ideally we would not use hard-wired operators below but instead use
+			 *	opclasses.  However, mixed data types and other issues make this
+			 *	difficult:  http://archives.postgresql.org/pgsql-hackers/2008-08/msg01142.php
+			 */			
 			| a_expr BETWEEN opt_asymmetric b_expr AND b_expr		%prec BETWEEN
 				{
 					$$ = (Node *) makeA_Expr(AEXPR_AND, NIL,

Original file line number	Diff line number	Diff line change
`@@ -11,7 +11,7 @@`
`11`	`11`	`*`
`12`	`12`	`*`
`13`	`13`	`* IDENTIFICATION`
`14`		`- * $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.651 2009/01/01 17:23:45 momjian Exp $`
	`14`	`+ * $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.652 2009/01/07 22:54:45 momjian Exp $`
`15`	`15`	`*`
`16`	`16`	`* HISTORY`
`17`	`17`	`* AUTHOR DATE MAJOR EVENT`
`@@ -8361,6 +8361,11 @@ a_expr: c_expr { $$ = $1; }`
`8361`	`8361`	`{`
`8362`	`8362`	`$$ = (Node ) makeSimpleA_Expr(AEXPR_OF, "<>", $1, (Node ) $6, @2);`
`8363`	`8363`	`}`
	`8364`	`+ /*`
	`8365`	`+ * Ideally we would not use hard-wired operators below but instead use`
	`8366`	`+ * opclasses. However, mixed data types and other issues make this`
	`8367`	`+ * difficult: http://archives.postgresql.org/pgsql-hackers/2008-08/msg01142.php`
	`8368`	`+ */`
`8364`	`8369`	`\| a_expr BETWEEN opt_asymmetric b_expr AND b_expr %prec BETWEEN`
`8365`	`8370`	`{`
`8366`	`8371`	`$$ = (Node *) makeA_Expr(AEXPR_AND, NIL,`