Fix list partition constraints for partition keys of array type.

The old code generated always generated a constraint of the form
col = ANY(ARRAY[val1, val2, ...]), but that's invalid when col is an
array type.  Instead, generate col = val when there's only one value,
col = val1 OR col = val2 OR ... when there are multiple values and
col is of array type, and the old form when there are multiple values
and col is not of an array type.

As a side benefit, this makes constraint exclusion able to prune
a list partition declared to accept a single Boolean value, which
didn't work before.

Amit Langote, reviewed by Etsuro Fujita

Discussion: http://postgr.es/m/[email protected]

1 files changed, 67 insertions, 31 deletions

diff --git a/src/backend/catalog/partition.c b/src/backend/catalog/partition.c
index e69bbc0345b..45945511f07 100644
--- a/src/backend/catalog/partition.c
+++ b/src/backend/catalog/partition.c
@@ -1625,18 +1625,60 @@ make_partition_op_expr(PartitionKey key, int keynum,
 	{
 		case PARTITION_STRATEGY_LIST:
 			{
-				ScalarArrayOpExpr *saopexpr;
-
-				/* Build leftop = ANY (rightop) */
-				saopexpr = makeNode(ScalarArrayOpExpr);
-				saopexpr->opno = operoid;
-				saopexpr->opfuncid = get_opcode(operoid);
-				saopexpr->useOr = true;
-				saopexpr->inputcollid = key->partcollation[keynum];
-				saopexpr->args = list_make2(arg1, arg2);
-				saopexpr->location = -1;
-
-				result = (Expr *) saopexpr;
+				List	   *elems = (List *) arg2;
+				int			nelems = list_length(elems);
+
+				Assert(nelems >= 1);
+				Assert(keynum == 0);
+
+				if (nelems > 1 &&
+					!type_is_array(key->parttypid[keynum]))
+				{
+					ArrayExpr  *arrexpr;
+					ScalarArrayOpExpr *saopexpr;
+
+					/* Construct an ArrayExpr for the right-hand inputs */
+					arrexpr = makeNode(ArrayExpr);
+					arrexpr->array_typeid =
+									get_array_type(key->parttypid[keynum]);
+					arrexpr->array_collid = key->parttypcoll[keynum];
+					arrexpr->element_typeid = key->parttypid[keynum];
+					arrexpr->elements = elems;
+					arrexpr->multidims = false;
+					arrexpr->location = -1;
+
+					/* Build leftop = ANY (rightop) */
+					saopexpr = makeNode(ScalarArrayOpExpr);
+					saopexpr->opno = operoid;
+					saopexpr->opfuncid = get_opcode(operoid);
+					saopexpr->useOr = true;
+					saopexpr->inputcollid = key->partcollation[keynum];
+					saopexpr->args = list_make2(arg1, arrexpr);
+					saopexpr->location = -1;
+
+					result = (Expr *) saopexpr;
+				}
+				else
+				{
+					List	   *elemops = NIL;
+					ListCell   *lc;
+
+					foreach (lc, elems)
+					{
+						Expr   *elem = lfirst(lc),
+							   *elemop;
+
+						elemop = make_opclause(operoid,
+											   BOOLOID,
+											   false,
+											   arg1, elem,
+											   InvalidOid,
+											   key->partcollation[keynum]);
+						elemops = lappend(elemops, elemop);
+					}
+
+					result = nelems > 1 ? makeBoolExpr(OR_EXPR, elemops, -1) : linitial(elemops);
+				}
 				break;
 			}
 
@@ -1758,11 +1800,10 @@ get_qual_for_list(Relation parent, PartitionBoundSpec *spec)
 	PartitionKey key = RelationGetPartitionKey(parent);
 	List	   *result;
 	Expr	   *keyCol;
-	ArrayExpr  *arr;
 	Expr	   *opexpr;
 	NullTest   *nulltest;
 	ListCell   *cell;
-	List	   *arrelems = NIL;
+	List	   *elems = NIL;
 	bool		list_has_null = false;
 
 	/*
@@ -1828,7 +1869,7 @@ get_qual_for_list(Relation parent, PartitionBoundSpec *spec)
 							false,	/* isnull */
 							key->parttypbyval[0]);
 
-			arrelems = lappend(arrelems, val);
+			elems = lappend(elems, val);
 		}
 	}
 	else
@@ -1843,30 +1884,25 @@ get_qual_for_list(Relation parent, PartitionBoundSpec *spec)
 			if (val->constisnull)
 				list_has_null = true;
 			else
-				arrelems = lappend(arrelems, copyObject(val));
+				elems = lappend(elems, copyObject(val));
 		}
 	}
 
-	if (arrelems)
+	if (elems)
 	{
-		/* Construct an ArrayExpr for the non-null partition values */
-		arr = makeNode(ArrayExpr);
-		arr->array_typeid = !type_is_array(key->parttypid[0])
-			? get_array_type(key->parttypid[0])
-			: key->parttypid[0];
-		arr->array_collid = key->parttypcoll[0];
-		arr->element_typeid = key->parttypid[0];
-		arr->elements = arrelems;
-		arr->multidims = false;
-		arr->location = -1;
-
-		/* Generate the main expression, i.e., keyCol = ANY (arr) */
+		/*
+		 * Generate the operator expression from the non-null partition
+		 * values.
+		 */
 		opexpr = make_partition_op_expr(key, 0, BTEqualStrategyNumber,
-										keyCol, (Expr *) arr);
+										keyCol, (Expr *) elems);
 	}
 	else
 	{
-		/* If there are no partition values, we don't need an = ANY expr */
+		/*
+		 * If there are no partition values, we don't need an operator
+		 * expression.
+		 */
 		opexpr = NULL;
 	}