From d75386a3fd34d8902667474318c2ebe40978de32 Mon Sep 17 00:00:00 2001
From: Alexander Korotkov <akorotkov@postgresql.org>
Date: Fri, 20 Sep 2019 15:31:12 +0300
Subject: [PATCH] Provide stable test for NULL-values in KNN SP-GiST
f5f084fc3e has removed test because of its instability. This commit provides
alternative test with determined ordering using extra ORDER BY expression.
Backpatch-through: 12
---
src/test/regress/expected/create_index_spgist.out | 10 ++++++++++
src/test/regress/sql/create_index_spgist.sql | 4 ++++
2 files changed, 14 insertions(+)
diff --git a/src/test/regress/expected/create_index_spgist.out b/src/test/regress/expected/create_index_spgist.out
index 81b4a67c390..1dd110dfc51 100644
--- a/src/test/regress/expected/create_index_spgist.out
+++ b/src/test/regress/expected/create_index_spgist.out
@@ -555,6 +555,16 @@ WHERE seq.dist IS DISTINCT FROM idx.dist;
---+------+---+---+------+---
(0 rows)
+-- check ORDER BY distance to NULL
+SELECT (SELECT p FROM kd_point_tbl ORDER BY p <-> pt, p <-> '0,0' LIMIT 1)
+FROM (VALUES (point '1,2'), (NULL), ('1234,5678')) pts(pt);
+ p
+-------------
+ (59,21)
+ (59,21)
+ (1239,5647)
+(3 rows)
+
EXPLAIN (COSTS OFF)
SELECT count(*) FROM radix_text_tbl WHERE t = 'P0123456789abcdef';
QUERY PLAN
diff --git a/src/test/regress/sql/create_index_spgist.sql b/src/test/regress/sql/create_index_spgist.sql
index 66d77286356..68632e3732e 100644
--- a/src/test/regress/sql/create_index_spgist.sql
+++ b/src/test/regress/sql/create_index_spgist.sql
@@ -225,6 +225,10 @@ SELECT * FROM quad_point_tbl_ord_seq3 seq FULL JOIN kd_point_tbl_ord_idx3 idx
ON seq.n = idx.n
WHERE seq.dist IS DISTINCT FROM idx.dist;
+-- check ORDER BY distance to NULL
+SELECT (SELECT p FROM kd_point_tbl ORDER BY p <-> pt, p <-> '0,0' LIMIT 1)
+FROM (VALUES (point '1,2'), (NULL), ('1234,5678')) pts(pt);
+
EXPLAIN (COSTS OFF)
SELECT count(*) FROM radix_text_tbl WHERE t = 'P0123456789abcdef';
--
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