1 files changed, 39 insertions, 30 deletions

diff --git a/src/backend/utils/adt/numeric.c b/src/backend/utils/adt/numeric.c
index 45cd1a0664f..1c9deebc1dd 100644
--- a/src/backend/utils/adt/numeric.c
+++ b/src/backend/utils/adt/numeric.c
@@ -34,6 +34,7 @@
 #include "libpq/pqformat.h"
 #include "miscadmin.h"
 #include "nodes/nodeFuncs.h"
+#include "nodes/supportnodes.h"
 #include "utils/array.h"
 #include "utils/builtins.h"
 #include "utils/float.h"
@@ -890,45 +891,53 @@ numeric_send(PG_FUNCTION_ARGS)
 
 
 /*
- * numeric_transform() -
+ * numeric_support()
  *
- * Flatten calls to numeric's length coercion function that solely represent
- * increases in allowable precision.  Scale changes mutate every datum, so
- * they are unoptimizable.  Some values, e.g. 1E-1001, can only fit into an
- * unconstrained numeric, so a change from an unconstrained numeric to any
- * constrained numeric is also unoptimizable.
+ * Planner support function for the numeric() length coercion function.
+ *
+ * Flatten calls that solely represent increases in allowable precision.
+ * Scale changes mutate every datum, so they are unoptimizable.  Some values,
+ * e.g. 1E-1001, can only fit into an unconstrained numeric, so a change from
+ * an unconstrained numeric to any constrained numeric is also unoptimizable.
  */
 Datum
-numeric_transform(PG_FUNCTION_ARGS)
+numeric_support(PG_FUNCTION_ARGS)
 {
-	FuncExpr   *expr = castNode(FuncExpr, PG_GETARG_POINTER(0));
+	Node	   *rawreq = (Node *) PG_GETARG_POINTER(0);
 	Node	   *ret = NULL;
-	Node	   *typmod;
 
-	Assert(list_length(expr->args) >= 2);
+	if (IsA(rawreq, SupportRequestSimplify))
+	{
+		SupportRequestSimplify *req = (SupportRequestSimplify *) rawreq;
+		FuncExpr   *expr = req->fcall;
+		Node	   *typmod;
 
-	typmod = (Node *) lsecond(expr->args);
+		Assert(list_length(expr->args) >= 2);
 
-	if (IsA(typmod, Const) &&!((Const *) typmod)->constisnull)
-	{
-		Node	   *source = (Node *) linitial(expr->args);
-		int32		old_typmod = exprTypmod(source);
-		int32		new_typmod = DatumGetInt32(((Const *) typmod)->constvalue);
-		int32		old_scale = (old_typmod - VARHDRSZ) & 0xffff;
-		int32		new_scale = (new_typmod - VARHDRSZ) & 0xffff;
-		int32		old_precision = (old_typmod - VARHDRSZ) >> 16 & 0xffff;
-		int32		new_precision = (new_typmod - VARHDRSZ) >> 16 & 0xffff;
+		typmod = (Node *) lsecond(expr->args);
 
-		/*
-		 * If new_typmod < VARHDRSZ, the destination is unconstrained; that's
-		 * always OK.  If old_typmod >= VARHDRSZ, the source is constrained,
-		 * and we're OK if the scale is unchanged and the precision is not
-		 * decreasing.  See further notes in function header comment.
-		 */
-		if (new_typmod < (int32) VARHDRSZ ||
-			(old_typmod >= (int32) VARHDRSZ &&
-			 new_scale == old_scale && new_precision >= old_precision))
-			ret = relabel_to_typmod(source, new_typmod);
+		if (IsA(typmod, Const) &&!((Const *) typmod)->constisnull)
+		{
+			Node	   *source = (Node *) linitial(expr->args);
+			int32		old_typmod = exprTypmod(source);
+			int32		new_typmod = DatumGetInt32(((Const *) typmod)->constvalue);
+			int32		old_scale = (old_typmod - VARHDRSZ) & 0xffff;
+			int32		new_scale = (new_typmod - VARHDRSZ) & 0xffff;
+			int32		old_precision = (old_typmod - VARHDRSZ) >> 16 & 0xffff;
+			int32		new_precision = (new_typmod - VARHDRSZ) >> 16 & 0xffff;
+
+			/*
+			 * If new_typmod < VARHDRSZ, the destination is unconstrained;
+			 * that's always OK.  If old_typmod >= VARHDRSZ, the source is
+			 * constrained, and we're OK if the scale is unchanged and the
+			 * precision is not decreasing.  See further notes in function
+			 * header comment.
+			 */
+			if (new_typmod < (int32) VARHDRSZ ||
+				(old_typmod >= (int32) VARHDRSZ &&
+				 new_scale == old_scale && new_precision >= old_precision))
+				ret = relabel_to_typmod(source, new_typmod);
+		}
 	}
 
 	PG_RETURN_POINTER(ret);