From 9ba37b2cb6a174b37fc51d0649ef73e56eae27fc Mon Sep 17 00:00:00 2001
From: Michael Paquier
Date: Tue, 7 Feb 2023 09:03:54 +0900
Subject: Include values of A_Const nodes in query jumbling

Like the implementation for node copy, write and read, this node
requires a custom implementation so as the query jumbling is able to
consider the correct value assigned to it, depending on its type (int,
float, bool, string, bitstring).

Based on a dump of pg_stat_statements from the regression database, this
would confuse the query jumbling of the following queries:
- SET.
- COPY TO with SELECT queries.
- START TRANSACTION with different isolation levels.
- ALTER TABLE with default expressions.
- CREATE TABLE with partition bounds.

Note that there may be a long-term argument in tracking the location of
such nodes so as query strings holding such nodes could be normalized,
but this is left as a separate discussion.

Oversight in 3db72eb.

Discussion: https://postgr.es/m/Y9+HuYslMAP6yyPb@paquier.xyz
---
 src/backend/nodes/queryjumblefuncs.c | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

(limited to 'src/backend')

diff --git a/src/backend/nodes/queryjumblefuncs.c b/src/backend/nodes/queryjumblefuncs.c
index 223d1bc8262..d7fd72d70f2 100644
--- a/src/backend/nodes/queryjumblefuncs.c
+++ b/src/backend/nodes/queryjumblefuncs.c
@@ -49,6 +49,7 @@ static void AppendJumble(JumbleState *jstate,
 						 const unsigned char *item, Size size);
 static void RecordConstLocation(JumbleState *jstate, int location);
 static void _jumbleNode(JumbleState *jstate, Node *node);
+static void _jumbleA_Const(JumbleState *jstate, Node *node);
 static void _jumbleList(JumbleState *jstate, Node *node);
 static void _jumbleRangeTblEntry(JumbleState *jstate, Node *node);
 
@@ -313,6 +314,40 @@ _jumbleList(JumbleState *jstate, Node *node)
 	}
 }
 
+static void
+_jumbleA_Const(JumbleState *jstate, Node *node)
+{
+	A_Const    *expr = (A_Const *) node;
+
+	JUMBLE_FIELD(isnull);
+	if (!expr->isnull)
+	{
+		JUMBLE_FIELD(val.node.type);
+		switch (nodeTag(&expr->val))
+		{
+			case T_Integer:
+				JUMBLE_FIELD(val.ival.ival);
+				break;
+			case T_Float:
+				JUMBLE_STRING(val.fval.fval);
+				break;
+			case T_Boolean:
+				JUMBLE_FIELD(val.boolval.boolval);
+				break;
+			case T_String:
+				JUMBLE_STRING(val.sval.sval);
+				break;
+			case T_BitString:
+				JUMBLE_STRING(val.bsval.bsval);
+				break;
+			default:
+				elog(ERROR, "unrecognized node type: %d",
+					 (int) nodeTag(&expr->val));
+				break;
+		}
+	}
+}
+
 static void
 _jumbleRangeTblEntry(JumbleState *jstate, Node *node)
 {
-- 
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