Change the parser to translate "foo [NOT] IN (expression-list)" to

ScalarArrayOpExpr when possible, that is, whenever there is an array type
for the values of the expression list.  This completes the project I've
been working on to improve the speed of index searches with long IN lists,
as per discussion back in mid-October.

I did not force initdb, but until you do one you will see failures in the
"rules" regression test, because some of the standard system views use IN
and their compiled formats have changed.

Author: tglsfdc

src/backend/nodes/outfuncs.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/outfuncs.c,v 1.263 2005/11/26 22:14:56 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/outfuncs.c,v 1.264 2005/11/28 04:35:30 tgl Exp $
  *
  * NOTES
  *	  Every node type that can appear in stored rules' parsetrees *must*
@@ -1597,6 +1597,10 @@ _outAExpr(StringInfo str, A_Expr *node)
 			appendStringInfo(str, " OF ");
 			WRITE_NODE_FIELD(name);
 			break;
+		case AEXPR_IN:
+			appendStringInfo(str, " IN ");
+			WRITE_NODE_FIELD(name);
+			break;
 		default:
 			appendStringInfo(str, " ??");
 			break;
@@ -1658,6 +1662,7 @@ _outAConst(StringInfo str, A_Const *node)
 {
 	WRITE_NODE_TYPE("A_CONST");
 
+	appendStringInfo(str, " :val ");
 	_outValue(str, &(node->val));
 	WRITE_NODE_FIELD(typename);
 }

src/backend/parser/gram.y

@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.515 2005/11/22 15:24:17 adunstan Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.516 2005/11/28 04:35:31 tgl Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -6721,7 +6721,7 @@ a_expr:		c_expr									{ $$ = $1; }
 				}
 			| a_expr IS NOT OF '(' type_list ')'		%prec IS
 				{
-					$$ = (Node *) makeSimpleA_Expr(AEXPR_OF, "!=", $1, (Node *) $6);
+					$$ = (Node *) makeSimpleA_Expr(AEXPR_OF, "<>", $1, (Node *) $6);
 				}
 			| a_expr BETWEEN opt_asymmetric b_expr AND b_expr		%prec BETWEEN
 				{
@@ -6760,38 +6760,30 @@ a_expr:		c_expr									{ $$ = $1; }
 					/* in_expr returns a SubLink or a list of a_exprs */
 					if (IsA($3, SubLink))
 					{
-							SubLink *n = (SubLink *)$3;
-							n->subLinkType = ANY_SUBLINK;
-							if (IsA($1, RowExpr))
-								n->lefthand = ((RowExpr *) $1)->args;
-							else
-								n->lefthand = list_make1($1);
-							n->operName = list_make1(makeString("="));
-							$$ = (Node *)n;
+						/* generate foo = ANY (subquery) */
+						SubLink *n = (SubLink *) $3;
+						n->subLinkType = ANY_SUBLINK;
+						if (IsA($1, RowExpr))
+							n->lefthand = ((RowExpr *) $1)->args;
+						else
+							n->lefthand = list_make1($1);
+						n->operName = list_make1(makeString("="));
+						$$ = (Node *)n;
 					}
 					else
 					{
-						Node *n = NULL;
-						ListCell *l;
-						foreach(l, (List *) $3)
-						{
-							Node *cmp;
-							cmp = (Node *) makeSimpleA_Expr(AEXPR_OP, "=", $1, lfirst(l));
-							if (n == NULL)
-								n = cmp;
-							else
-								n = (Node *) makeA_Expr(AEXPR_OR, NIL, n, cmp);
-						}
-						$$ = n;
+						/* generate scalar IN expression */
+						$$ = (Node *) makeSimpleA_Expr(AEXPR_IN, "=", $1, $3);
 					}
 				}
 			| a_expr NOT IN_P in_expr
 				{
 					/* in_expr returns a SubLink or a list of a_exprs */
 					if (IsA($4, SubLink))
 					{
-						/* Make an IN node */
-						SubLink *n = (SubLink *)$4;
+						/* generate NOT (foo = ANY (subquery)) */
+						/* Make an = ANY node */
+						SubLink *n = (SubLink *) $4;
 						n->subLinkType = ANY_SUBLINK;
 						if (IsA($1, RowExpr))
 							n->lefthand = ((RowExpr *) $1)->args;
@@ -6803,18 +6795,8 @@ a_expr:		c_expr									{ $$ = $1; }
 					}
 					else
 					{
-						Node *n = NULL;
-						ListCell *l;
-						foreach(l, (List *) $4)
-						{
-							Node *cmp;
-							cmp = (Node *) makeSimpleA_Expr(AEXPR_OP, "<>", $1, lfirst(l));
-							if (n == NULL)
-								n = cmp;
-							else
-								n = (Node *) makeA_Expr(AEXPR_AND, NIL, n, cmp);
-						}
-						$$ = n;
+						/* generate scalar NOT IN expression */
+						$$ = (Node *) makeSimpleA_Expr(AEXPR_IN, "<>", $1, $4);
 					}
 				}
 			| a_expr subquery_Op sub_type select_with_parens %prec Op
@@ -6904,7 +6886,7 @@ b_expr:		c_expr
 				}
 			| b_expr IS NOT OF '(' type_list ')'	%prec IS
 				{
-					$$ = (Node *) makeSimpleA_Expr(AEXPR_OF, "!=", $1, (Node *) $6);
+					$$ = (Node *) makeSimpleA_Expr(AEXPR_OF, "<>", $1, (Node *) $6);
 				}
 		;