From f2a64348021c7dba1f96d0c8b4e3e253f635b019 Mon Sep 17 00:00:00 2001
From: amit <amitlangote09@gmail.com>
Date: Wed, 28 Dec 2016 10:10:26 +0900
Subject: [PATCH 1/3] Set ecxt_scantuple correctly for tuple-routing

In 2ac3ef7a01df859c62d0a02333b646d65eaec5ff, we changed things so that
it's possible for a different TupleTableSlot to be used for partitioned
tables at successively lower levels.  If we do end up changing the slot
from the original, we must update ecxt_scantuple to point to the new one
for partition key of the tuple to be computed correctly.

Also update the regression tests so that the code manipulating
ecxt_scantuple is covered.

Reported by: Rajkumar Raghuwanshi
Patch by: Amit Langote
Reports: https://www.postgresql.org/message-id/CAKcux6%3Dm1qyqB2k6cjniuMMrYXb75O-MB4qGQMu8zg-iGGLjDw%40mail.gmail.com
---
 src/backend/catalog/partition.c      | 29 ++++++++++++++++++++++-------
 src/backend/executor/execMain.c      |  2 --
 src/test/regress/expected/insert.out |  2 +-
 src/test/regress/sql/insert.sql      |  2 +-
 4 files changed, 24 insertions(+), 11 deletions(-)

diff --git a/src/backend/catalog/partition.c b/src/backend/catalog/partition.c
index f54e1bdf3f..0de1cf245a 100644
--- a/src/backend/catalog/partition.c
+++ b/src/backend/catalog/partition.c
@@ -1643,7 +1643,10 @@ get_partition_for_tuple(PartitionDispatch *pd,
 	bool		isnull[PARTITION_MAX_KEYS];
 	int			cur_offset,
 				cur_index;
-	int			i;
+	int			i,
+				result;
+	ExprContext *ecxt = GetPerTupleExprContext(estate);
+	TupleTableSlot *ecxt_scantuple_old = ecxt->ecxt_scantuple;
 
 	/* start with the root partitioned table */
 	parent = pd[0];
@@ -1672,7 +1675,14 @@ get_partition_for_tuple(PartitionDispatch *pd,
 			slot = myslot;
 		}
 
-		/* Extract partition key from tuple */
+		/*
+		 * Extract partition key from tuple; FormPartitionKeyDatum() expects
+		 * ecxt_scantuple to point to the correct tuple slot (which might be
+		 * different from the slot we received from the caller if the
+		 * partitioned table of the current level has different tuple
+		 * descriptor from its parent).
+		 */
+		ecxt->ecxt_scantuple = slot;
 		FormPartitionKeyDatum(parent, slot, estate, values, isnull);
 
 		if (key->strategy == PARTITION_STRATEGY_RANGE)
@@ -1727,16 +1737,21 @@ get_partition_for_tuple(PartitionDispatch *pd,
 		 */
 		if (cur_index < 0)
 		{
+			result = -1;
 			*failed_at = RelationGetRelid(parent->reldesc);
-			return -1;
+			break;
 		}
-		else if (parent->indexes[cur_index] < 0)
-			parent = pd[-parent->indexes[cur_index]];
-		else
+		else if (parent->indexes[cur_index] >= 0)
+		{
+			result = parent->indexes[cur_index];
 			break;
+		}
+		else
+			parent = pd[-parent->indexes[cur_index]];
 	}
 
-	return parent->indexes[cur_index];
+	ecxt->ecxt_scantuple = ecxt_scantuple_old;
+	return result;
 }
 
 /*
diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index ff277d300a..6a9bc8372f 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -3167,9 +3167,7 @@ ExecFindPartition(ResultRelInfo *resultRelInfo, PartitionDispatch *pd,
 {
 	int		result;
 	Oid		failed_at;
-	ExprContext *econtext = GetPerTupleExprContext(estate);
 
-	econtext->ecxt_scantuple = slot;
 	result = get_partition_for_tuple(pd, slot, estate, &failed_at);
 	if (result < 0)
 	{
diff --git a/src/test/regress/expected/insert.out b/src/test/regress/expected/insert.out
index ca3134c34c..1c7b8047ee 100644
--- a/src/test/regress/expected/insert.out
+++ b/src/test/regress/expected/insert.out
@@ -302,7 +302,7 @@ drop cascades to table part_ee_ff1
 drop cascades to table part_ee_ff2
 -- more tests for certain multi-level partitioning scenarios
 create table p (a int, b int) partition by range (a, b);
-create table p1 (b int, a int not null) partition by range (b);
+create table p1 (b int not null, a int not null) partition by range ((b+0));
 create table p11 (like p1);
 alter table p11 drop a;
 alter table p11 add a int;
diff --git a/src/test/regress/sql/insert.sql b/src/test/regress/sql/insert.sql
index 09c9879da1..c25dc14575 100644
--- a/src/test/regress/sql/insert.sql
+++ b/src/test/regress/sql/insert.sql
@@ -173,7 +173,7 @@ drop table list_parted cascade;
 
 -- more tests for certain multi-level partitioning scenarios
 create table p (a int, b int) partition by range (a, b);
-create table p1 (b int, a int not null) partition by range (b);
+create table p1 (b int not null, a int not null) partition by range ((b+0));
 create table p11 (like p1);
 alter table p11 drop a;
 alter table p11 add a int;
-- 
2.11.0