From 003788e81e7f72bc545b509e1517a672d891273b Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Thu, 23 Sep 2010 15:16:49 -0400
Subject: [PATCH] Make _outPathInfo print the relid set of the path's parent
rel.
We can't actually print the parent RelOptInfo in toto, because that would
lead to infinite recursion. But it's safe enough to reach into the parent
and print its identifying relids, and that makes it a whole lot easier
to figure out what a Path represents. Should have done this years ago.
---
src/backend/nodes/outfuncs.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index e62fe818821..3b30d4f81c0 100644
--- a/src/backend/nodes/outfuncs.c
+++ b/src/backend/nodes/outfuncs.c
@@ -1352,12 +1352,15 @@ _outFromExpr(StringInfo str, FromExpr *node)
/*
* print the basic stuff of all nodes that inherit from Path
*
- * Note we do NOT print the parent, else we'd be in infinite recursion
+ * Note we do NOT print the parent, else we'd be in infinite recursion.
+ * We can print the parent's relids for identification purposes, though.
*/
static void
_outPathInfo(StringInfo str, Path *node)
{
WRITE_ENUM_FIELD(pathtype, NodeTag);
+ appendStringInfo(str, " :parent_relids ");
+ _outBitmapset(str, node->parent->relids);
WRITE_FLOAT_FIELD(startup_cost, "%.2f");
WRITE_FLOAT_FIELD(total_cost, "%.2f");
WRITE_NODE_FIELD(pathkeys);
--
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