From 3c987fa79d1d2341869de226879a7201e035040a Mon Sep 17 00:00:00 2001
From: Andres Freund <andres@anarazel.de>
Date: Thu, 24 Oct 2019 13:58:40 -0700
Subject: [PATCH v1 1/2] Add tests for tuplesort.c.

Author:
Reviewed-By:
Discussion: https://postgr.es/m/
Backpatch:
---
 src/test/regress/expected/tuplesort.out | 591 ++++++++++++++++++++++++
 src/test/regress/parallel_schedule      |   2 +-
 src/test/regress/sql/tuplesort.sql      | 258 +++++++++++
 3 files changed, 850 insertions(+), 1 deletion(-)
 create mode 100644 src/test/regress/expected/tuplesort.out
 create mode 100644 src/test/regress/sql/tuplesort.sql

diff --git a/src/test/regress/expected/tuplesort.out b/src/test/regress/expected/tuplesort.out
new file mode 100644
index 00000000000..d3b99df73ae
--- /dev/null
+++ b/src/test/regress/expected/tuplesort.out
@@ -0,0 +1,591 @@
+-- only use parallelism when explicitly intending to do so
+SET max_parallel_maintenance_workers = 0;
+SET max_parallel_workers = 0;
+-- A table with with contents that, when sorted, triggers abbreviated
+-- key aborts. One easy way to achieve that is to use uuids that all
+-- have the same prefix, as abbreviated keys for uuids just use the
+-- first sizeof(Datum) bytes.
+DROP TABLE IF EXISTS abbrev_abort_uuids;
+NOTICE:  table "abbrev_abort_uuids" does not exist, skipping
+CREATE TABLE abbrev_abort_uuids (
+    id serial not null,
+    abort_increasing uuid,
+    abort_decreasing uuid,
+    noabort_increasing uuid,
+    noabort_decreasing uuid);
+INSERT INTO abbrev_abort_uuids (abort_increasing, abort_decreasing, noabort_increasing, noabort_decreasing)
+    SELECT
+        ('00000000-0000-0000-0000-'||to_char(g.i, '000000000000FM'))::uuid abort_increasing,
+        ('00000000-0000-0000-0000-'||to_char(20000 - g.i, '000000000000FM'))::uuid abort_decreasing,
+        (to_char(g.i % 10009, '00000000FM')||'-0000-0000-0000-'||to_char(g.i, '000000000000FM'))::uuid noabort_increasing,
+        (to_char(((20000 - g.i) % 10009), '00000000FM')||'-0000-0000-0000-'||to_char(20000 - g.i, '000000000000FM'))::uuid noabort_decreasing
+    FROM generate_series(0, 20000, 1) g(i);
+-- and a few NULLs
+INSERT INTO abbrev_abort_uuids(id) VALUES(0);
+INSERT INTO abbrev_abort_uuids DEFAULT VALUES;
+INSERT INTO abbrev_abort_uuids DEFAULT VALUES;
+-- add just a few duplicates
+INSERT INTO abbrev_abort_uuids (abort_increasing, abort_decreasing, noabort_increasing, noabort_decreasing)
+    SELECT abort_increasing, abort_decreasing, noabort_increasing, noabort_decreasing
+    FROM abbrev_abort_uuids
+    WHERE (id < 10 OR id > 19990) AND id % 3 = 0 AND abort_increasing is not null;
+----
+-- Check sort node uses of tuplesort wrt. abbreviated keys
+----
+-- plain sort triggering abbreviated abort
+SELECT abort_increasing, abort_decreasing FROM abbrev_abort_uuids ORDER BY abort_increasing OFFSET 20000 - 4;
+           abort_increasing           |           abort_decreasing           
+--------------------------------------+--------------------------------------
+ 00000000-0000-0000-0000-000000019992 | 00000000-0000-0000-0000-000000000008
+ 00000000-0000-0000-0000-000000019993 | 00000000-0000-0000-0000-000000000007
+ 00000000-0000-0000-0000-000000019994 | 00000000-0000-0000-0000-000000000006
+ 00000000-0000-0000-0000-000000019994 | 00000000-0000-0000-0000-000000000006
+ 00000000-0000-0000-0000-000000019995 | 00000000-0000-0000-0000-000000000005
+ 00000000-0000-0000-0000-000000019996 | 00000000-0000-0000-0000-000000000004
+ 00000000-0000-0000-0000-000000019997 | 00000000-0000-0000-0000-000000000003
+ 00000000-0000-0000-0000-000000019997 | 00000000-0000-0000-0000-000000000003
+ 00000000-0000-0000-0000-000000019998 | 00000000-0000-0000-0000-000000000002
+ 00000000-0000-0000-0000-000000019999 | 00000000-0000-0000-0000-000000000001
+ 00000000-0000-0000-0000-000000020000 | 00000000-0000-0000-0000-000000000000
+ 00000000-0000-0000-0000-000000020000 | 00000000-0000-0000-0000-000000000000
+                                      | 
+                                      | 
+                                      | 
+(15 rows)
+
+SELECT abort_increasing, abort_decreasing FROM abbrev_abort_uuids ORDER BY abort_decreasing NULLS FIRST OFFSET 20000 - 4;
+           abort_increasing           |           abort_decreasing           
+--------------------------------------+--------------------------------------
+ 00000000-0000-0000-0000-000000000011 | 00000000-0000-0000-0000-000000019989
+ 00000000-0000-0000-0000-000000000010 | 00000000-0000-0000-0000-000000019990
+ 00000000-0000-0000-0000-000000000009 | 00000000-0000-0000-0000-000000019991
+ 00000000-0000-0000-0000-000000000008 | 00000000-0000-0000-0000-000000019992
+ 00000000-0000-0000-0000-000000000008 | 00000000-0000-0000-0000-000000019992
+ 00000000-0000-0000-0000-000000000007 | 00000000-0000-0000-0000-000000019993
+ 00000000-0000-0000-0000-000000000006 | 00000000-0000-0000-0000-000000019994
+ 00000000-0000-0000-0000-000000000005 | 00000000-0000-0000-0000-000000019995
+ 00000000-0000-0000-0000-000000000005 | 00000000-0000-0000-0000-000000019995
+ 00000000-0000-0000-0000-000000000004 | 00000000-0000-0000-0000-000000019996
+ 00000000-0000-0000-0000-000000000003 | 00000000-0000-0000-0000-000000019997
+ 00000000-0000-0000-0000-000000000002 | 00000000-0000-0000-0000-000000019998
+ 00000000-0000-0000-0000-000000000002 | 00000000-0000-0000-0000-000000019998
+ 00000000-0000-0000-0000-000000000001 | 00000000-0000-0000-0000-000000019999
+ 00000000-0000-0000-0000-000000000000 | 00000000-0000-0000-0000-000000020000
+(15 rows)
+
+-- plain sort not triggering abbreviated abort
+SELECT noabort_increasing, noabort_decreasing FROM abbrev_abort_uuids ORDER BY noabort_increasing OFFSET 20000 - 4;
+          noabort_increasing          |          noabort_decreasing          
+--------------------------------------+--------------------------------------
+ 00009997-0000-0000-0000-000000009997 | 00010003-0000-0000-0000-000000010003
+ 00009998-0000-0000-0000-000000009998 | 00010002-0000-0000-0000-000000010002
+ 00009999-0000-0000-0000-000000009999 | 00010001-0000-0000-0000-000000010001
+ 00010000-0000-0000-0000-000000010000 | 00010000-0000-0000-0000-000000010000
+ 00010001-0000-0000-0000-000000010001 | 00009999-0000-0000-0000-000000009999
+ 00010002-0000-0000-0000-000000010002 | 00009998-0000-0000-0000-000000009998
+ 00010003-0000-0000-0000-000000010003 | 00009997-0000-0000-0000-000000009997
+ 00010004-0000-0000-0000-000000010004 | 00009996-0000-0000-0000-000000009996
+ 00010005-0000-0000-0000-000000010005 | 00009995-0000-0000-0000-000000009995
+ 00010006-0000-0000-0000-000000010006 | 00009994-0000-0000-0000-000000009994
+ 00010007-0000-0000-0000-000000010007 | 00009993-0000-0000-0000-000000009993
+ 00010008-0000-0000-0000-000000010008 | 00009992-0000-0000-0000-000000009992
+                                      | 
+                                      | 
+                                      | 
+(15 rows)
+
+SELECT noabort_increasing, noabort_decreasing FROM abbrev_abort_uuids ORDER BY noabort_decreasing NULLS FIRST OFFSET 20000 - 4;
+          noabort_increasing          |          noabort_decreasing          
+--------------------------------------+--------------------------------------
+ 00010006-0000-0000-0000-000000010006 | 00009994-0000-0000-0000-000000009994
+ 00010005-0000-0000-0000-000000010005 | 00009995-0000-0000-0000-000000009995
+ 00010004-0000-0000-0000-000000010004 | 00009996-0000-0000-0000-000000009996
+ 00010003-0000-0000-0000-000000010003 | 00009997-0000-0000-0000-000000009997
+ 00010002-0000-0000-0000-000000010002 | 00009998-0000-0000-0000-000000009998
+ 00010001-0000-0000-0000-000000010001 | 00009999-0000-0000-0000-000000009999
+ 00010000-0000-0000-0000-000000010000 | 00010000-0000-0000-0000-000000010000
+ 00009999-0000-0000-0000-000000009999 | 00010001-0000-0000-0000-000000010001
+ 00009998-0000-0000-0000-000000009998 | 00010002-0000-0000-0000-000000010002
+ 00009997-0000-0000-0000-000000009997 | 00010003-0000-0000-0000-000000010003
+ 00009996-0000-0000-0000-000000009996 | 00010004-0000-0000-0000-000000010004
+ 00009995-0000-0000-0000-000000009995 | 00010005-0000-0000-0000-000000010005
+ 00009994-0000-0000-0000-000000009994 | 00010006-0000-0000-0000-000000010006
+ 00009993-0000-0000-0000-000000009993 | 00010007-0000-0000-0000-000000010007
+ 00009992-0000-0000-0000-000000009992 | 00010008-0000-0000-0000-000000010008
+(15 rows)
+
+-- bounded sort (disables abbreviated keys)
+SELECT abort_increasing, noabort_increasing FROM abbrev_abort_uuids ORDER BY abort_increasing LIMIT 5;
+           abort_increasing           |          noabort_increasing          
+--------------------------------------+--------------------------------------
+ 00000000-0000-0000-0000-000000000000 | 00000000-0000-0000-0000-000000000000
+ 00000000-0000-0000-0000-000000000001 | 00000001-0000-0000-0000-000000000001
+ 00000000-0000-0000-0000-000000000002 | 00000002-0000-0000-0000-000000000002
+ 00000000-0000-0000-0000-000000000002 | 00000002-0000-0000-0000-000000000002
+ 00000000-0000-0000-0000-000000000003 | 00000003-0000-0000-0000-000000000003
+(5 rows)
+
+SELECT abort_increasing, noabort_increasing FROM abbrev_abort_uuids ORDER BY noabort_increasing NULLS FIRST LIMIT 5;
+           abort_increasing           |          noabort_increasing          
+--------------------------------------+--------------------------------------
+                                      | 
+                                      | 
+                                      | 
+ 00000000-0000-0000-0000-000000000000 | 00000000-0000-0000-0000-000000000000
+ 00000000-0000-0000-0000-000000010009 | 00000000-0000-0000-0000-000000010009
+(5 rows)
+
+----
+-- Check index creation uses of tuplesort wrt. abbreviated keys
+----
+-- index creation using abbreviated keys successfully
+CREATE INDEX abbrev_abort_uuids__noabort_increasing_idx ON abbrev_abort_uuids (noabort_increasing);
+CREATE INDEX abbrev_abort_uuids__noabort_decreasing_idx ON abbrev_abort_uuids (noabort_decreasing);
+-- verify
+EXPLAIN SELECT id, noabort_increasing, noabort_decreasing FROM abbrev_abort_uuids ORDER BY noabort_increasing LIMIT 5;
+                                                            QUERY PLAN                                                             
+-----------------------------------------------------------------------------------------------------------------------------------
+ Limit  (cost=0.29..0.69 rows=5 width=36)
+   ->  Index Scan using abbrev_abort_uuids__noabort_increasing_idx on abbrev_abort_uuids  (cost=0.29..1608.45 rows=20011 width=36)
+(2 rows)
+
+SELECT id, noabort_increasing, noabort_decreasing FROM abbrev_abort_uuids ORDER BY noabort_increasing LIMIT 5;
+  id   |          noabort_increasing          |          noabort_decreasing          
+-------+--------------------------------------+--------------------------------------
+     1 | 00000000-0000-0000-0000-000000000000 | 00009991-0000-0000-0000-000000020000
+ 10010 | 00000000-0000-0000-0000-000000010009 | 00009991-0000-0000-0000-000000009991
+     2 | 00000001-0000-0000-0000-000000000001 | 00009990-0000-0000-0000-000000019999
+ 10011 | 00000001-0000-0000-0000-000000010010 | 00009990-0000-0000-0000-000000009990
+     3 | 00000002-0000-0000-0000-000000000002 | 00009989-0000-0000-0000-000000019998
+(5 rows)
+
+EXPLAIN SELECT id, noabort_increasing, noabort_decreasing FROM abbrev_abort_uuids ORDER BY noabort_decreasing LIMIT 5;
+                                                            QUERY PLAN                                                             
+-----------------------------------------------------------------------------------------------------------------------------------
+ Limit  (cost=0.29..0.69 rows=5 width=36)
+   ->  Index Scan using abbrev_abort_uuids__noabort_decreasing_idx on abbrev_abort_uuids  (cost=0.29..1608.45 rows=20011 width=36)
+(2 rows)
+
+SELECT id, noabort_increasing, noabort_decreasing FROM abbrev_abort_uuids ORDER BY noabort_decreasing LIMIT 5;
+  id   |          noabort_increasing          |          noabort_decreasing          
+-------+--------------------------------------+--------------------------------------
+ 20001 | 00009991-0000-0000-0000-000000020000 | 00000000-0000-0000-0000-000000000000
+ 20010 | 00009991-0000-0000-0000-000000020000 | 00000000-0000-0000-0000-000000000000
+  9992 | 00009991-0000-0000-0000-000000009991 | 00000000-0000-0000-0000-000000010009
+ 20000 | 00009990-0000-0000-0000-000000019999 | 00000001-0000-0000-0000-000000000001
+  9991 | 00009990-0000-0000-0000-000000009990 | 00000001-0000-0000-0000-000000010010
+(5 rows)
+
+-- index creation using abbreviated keys, hitting abort
+CREATE INDEX abbrev_abort_uuids__abort_increasing_idx ON abbrev_abort_uuids (abort_increasing);
+CREATE INDEX abbrev_abort_uuids__abort_decreasing_idx ON abbrev_abort_uuids (abort_decreasing);
+-- verify
+EXPLAIN SELECT id, abort_increasing, abort_decreasing FROM abbrev_abort_uuids ORDER BY abort_increasing LIMIT 5;
+                                                           QUERY PLAN                                                            
+---------------------------------------------------------------------------------------------------------------------------------
+ Limit  (cost=0.29..0.69 rows=5 width=36)
+   ->  Index Scan using abbrev_abort_uuids__abort_increasing_idx on abbrev_abort_uuids  (cost=0.29..1608.45 rows=20011 width=36)
+(2 rows)
+
+SELECT id, abort_increasing, abort_decreasing FROM abbrev_abort_uuids ORDER BY abort_increasing LIMIT 5;
+  id   |           abort_increasing           |           abort_decreasing           
+-------+--------------------------------------+--------------------------------------
+     1 | 00000000-0000-0000-0000-000000000000 | 00000000-0000-0000-0000-000000020000
+     2 | 00000000-0000-0000-0000-000000000001 | 00000000-0000-0000-0000-000000019999
+     3 | 00000000-0000-0000-0000-000000000002 | 00000000-0000-0000-0000-000000019998
+ 20004 | 00000000-0000-0000-0000-000000000002 | 00000000-0000-0000-0000-000000019998
+     4 | 00000000-0000-0000-0000-000000000003 | 00000000-0000-0000-0000-000000019997
+(5 rows)
+
+EXPLAIN SELECT id, abort_increasing, abort_decreasing FROM abbrev_abort_uuids ORDER BY abort_decreasing LIMIT 5;
+                                                           QUERY PLAN                                                            
+---------------------------------------------------------------------------------------------------------------------------------
+ Limit  (cost=0.29..0.69 rows=5 width=36)
+   ->  Index Scan using abbrev_abort_uuids__abort_decreasing_idx on abbrev_abort_uuids  (cost=0.29..1608.45 rows=20011 width=36)
+(2 rows)
+
+SELECT id, abort_increasing, abort_decreasing FROM abbrev_abort_uuids ORDER BY abort_decreasing LIMIT 5;
+  id   |           abort_increasing           |           abort_decreasing           
+-------+--------------------------------------+--------------------------------------
+ 20001 | 00000000-0000-0000-0000-000000020000 | 00000000-0000-0000-0000-000000000000
+ 20010 | 00000000-0000-0000-0000-000000020000 | 00000000-0000-0000-0000-000000000000
+ 20000 | 00000000-0000-0000-0000-000000019999 | 00000000-0000-0000-0000-000000000001
+ 19999 | 00000000-0000-0000-0000-000000019998 | 00000000-0000-0000-0000-000000000002
+ 19998 | 00000000-0000-0000-0000-000000019997 | 00000000-0000-0000-0000-000000000003
+(5 rows)
+
+----
+-- Check CLUSTER uses of tuplesort wrt. abbreviated keys
+----
+-- when aborting, increasing order
+BEGIN;
+SET LOCAL enable_indexscan = false;
+CLUSTER abbrev_abort_uuids USING abbrev_abort_uuids__abort_increasing_idx;
+-- head
+SELECT id, abort_increasing, abort_decreasing, noabort_increasing, noabort_decreasing
+FROM abbrev_abort_uuids
+ORDER BY ctid LIMIT 5;
+  id   |           abort_increasing           |           abort_decreasing           |          noabort_increasing          |          noabort_decreasing          
+-------+--------------------------------------+--------------------------------------+--------------------------------------+--------------------------------------
+     1 | 00000000-0000-0000-0000-000000000000 | 00000000-0000-0000-0000-000000020000 | 00000000-0000-0000-0000-000000000000 | 00009991-0000-0000-0000-000000020000
+     2 | 00000000-0000-0000-0000-000000000001 | 00000000-0000-0000-0000-000000019999 | 00000001-0000-0000-0000-000000000001 | 00009990-0000-0000-0000-000000019999
+     3 | 00000000-0000-0000-0000-000000000002 | 00000000-0000-0000-0000-000000019998 | 00000002-0000-0000-0000-000000000002 | 00009989-0000-0000-0000-000000019998
+ 20004 | 00000000-0000-0000-0000-000000000002 | 00000000-0000-0000-0000-000000019998 | 00000002-0000-0000-0000-000000000002 | 00009989-0000-0000-0000-000000019998
+     4 | 00000000-0000-0000-0000-000000000003 | 00000000-0000-0000-0000-000000019997 | 00000003-0000-0000-0000-000000000003 | 00009988-0000-0000-0000-000000019997
+(5 rows)
+
+-- tail
+SELECT id, abort_increasing, abort_decreasing, noabort_increasing, noabort_decreasing
+FROM abbrev_abort_uuids
+ORDER BY ctid DESC LIMIT 5;
+  id   |           abort_increasing           |           abort_decreasing           |          noabort_increasing          |          noabort_decreasing          
+-------+--------------------------------------+--------------------------------------+--------------------------------------+--------------------------------------
+     0 |                                      |                                      |                                      | 
+ 20002 |                                      |                                      |                                      | 
+ 20003 |                                      |                                      |                                      | 
+ 20001 | 00000000-0000-0000-0000-000000020000 | 00000000-0000-0000-0000-000000000000 | 00009991-0000-0000-0000-000000020000 | 00000000-0000-0000-0000-000000000000
+ 20010 | 00000000-0000-0000-0000-000000020000 | 00000000-0000-0000-0000-000000000000 | 00009991-0000-0000-0000-000000020000 | 00000000-0000-0000-0000-000000000000
+(5 rows)
+
+ROLLBACK;
+-- when aborting, decreasing order
+BEGIN;
+SET LOCAL enable_indexscan = false;
+CLUSTER abbrev_abort_uuids USING abbrev_abort_uuids__abort_decreasing_idx;
+-- head
+SELECT id, abort_increasing, abort_decreasing, noabort_increasing, noabort_decreasing
+FROM abbrev_abort_uuids
+ORDER BY ctid LIMIT 5;
+  id   |           abort_increasing           |           abort_decreasing           |          noabort_increasing          |          noabort_decreasing          
+-------+--------------------------------------+--------------------------------------+--------------------------------------+--------------------------------------
+ 20010 | 00000000-0000-0000-0000-000000020000 | 00000000-0000-0000-0000-000000000000 | 00009991-0000-0000-0000-000000020000 | 00000000-0000-0000-0000-000000000000
+ 20001 | 00000000-0000-0000-0000-000000020000 | 00000000-0000-0000-0000-000000000000 | 00009991-0000-0000-0000-000000020000 | 00000000-0000-0000-0000-000000000000
+ 20000 | 00000000-0000-0000-0000-000000019999 | 00000000-0000-0000-0000-000000000001 | 00009990-0000-0000-0000-000000019999 | 00000001-0000-0000-0000-000000000001
+ 19999 | 00000000-0000-0000-0000-000000019998 | 00000000-0000-0000-0000-000000000002 | 00009989-0000-0000-0000-000000019998 | 00000002-0000-0000-0000-000000000002
+ 20009 | 00000000-0000-0000-0000-000000019997 | 00000000-0000-0000-0000-000000000003 | 00009988-0000-0000-0000-000000019997 | 00000003-0000-0000-0000-000000000003
+(5 rows)
+
+-- tail
+SELECT id, abort_increasing, abort_decreasing, noabort_increasing, noabort_decreasing
+FROM abbrev_abort_uuids
+ORDER BY ctid DESC LIMIT 5;
+  id   |           abort_increasing           |           abort_decreasing           |          noabort_increasing          |          noabort_decreasing          
+-------+--------------------------------------+--------------------------------------+--------------------------------------+--------------------------------------
+     0 |                                      |                                      |                                      | 
+ 20002 |                                      |                                      |                                      | 
+ 20003 |                                      |                                      |                                      | 
+     1 | 00000000-0000-0000-0000-000000000000 | 00000000-0000-0000-0000-000000020000 | 00000000-0000-0000-0000-000000000000 | 00009991-0000-0000-0000-000000020000
+     2 | 00000000-0000-0000-0000-000000000001 | 00000000-0000-0000-0000-000000019999 | 00000001-0000-0000-0000-000000000001 | 00009990-0000-0000-0000-000000019999
+(5 rows)
+
+ROLLBACK;
+-- when not aborting, increasing order
+BEGIN;
+SET LOCAL enable_indexscan = false;
+CLUSTER abbrev_abort_uuids USING abbrev_abort_uuids__noabort_increasing_idx;
+-- head
+SELECT id, abort_increasing, abort_decreasing, noabort_increasing, noabort_decreasing
+FROM abbrev_abort_uuids
+ORDER BY ctid LIMIT 5;
+  id   |           abort_increasing           |           abort_decreasing           |          noabort_increasing          |          noabort_decreasing          
+-------+--------------------------------------+--------------------------------------+--------------------------------------+--------------------------------------
+     1 | 00000000-0000-0000-0000-000000000000 | 00000000-0000-0000-0000-000000020000 | 00000000-0000-0000-0000-000000000000 | 00009991-0000-0000-0000-000000020000
+ 10010 | 00000000-0000-0000-0000-000000010009 | 00000000-0000-0000-0000-000000009991 | 00000000-0000-0000-0000-000000010009 | 00009991-0000-0000-0000-000000009991
+     2 | 00000000-0000-0000-0000-000000000001 | 00000000-0000-0000-0000-000000019999 | 00000001-0000-0000-0000-000000000001 | 00009990-0000-0000-0000-000000019999
+ 10011 | 00000000-0000-0000-0000-000000010010 | 00000000-0000-0000-0000-000000009990 | 00000001-0000-0000-0000-000000010010 | 00009990-0000-0000-0000-000000009990
+ 20004 | 00000000-0000-0000-0000-000000000002 | 00000000-0000-0000-0000-000000019998 | 00000002-0000-0000-0000-000000000002 | 00009989-0000-0000-0000-000000019998
+(5 rows)
+
+-- tail
+SELECT id, abort_increasing, abort_decreasing, noabort_increasing, noabort_decreasing
+FROM abbrev_abort_uuids
+ORDER BY ctid DESC LIMIT 5;
+  id   |           abort_increasing           |           abort_decreasing           |          noabort_increasing          |          noabort_decreasing          
+-------+--------------------------------------+--------------------------------------+--------------------------------------+--------------------------------------
+     0 |                                      |                                      |                                      | 
+ 20002 |                                      |                                      |                                      | 
+ 20003 |                                      |                                      |                                      | 
+ 10009 | 00000000-0000-0000-0000-000000010008 | 00000000-0000-0000-0000-000000009992 | 00010008-0000-0000-0000-000000010008 | 00009992-0000-0000-0000-000000009992
+ 10008 | 00000000-0000-0000-0000-000000010007 | 00000000-0000-0000-0000-000000009993 | 00010007-0000-0000-0000-000000010007 | 00009993-0000-0000-0000-000000009993
+(5 rows)
+
+ROLLBACK;
+-- when no aborting, decreasing order
+BEGIN;
+SET LOCAL enable_indexscan = false;
+CLUSTER abbrev_abort_uuids USING abbrev_abort_uuids__noabort_decreasing_idx;
+-- head
+SELECT id, abort_increasing, abort_decreasing, noabort_increasing, noabort_decreasing
+FROM abbrev_abort_uuids
+ORDER BY ctid LIMIT 5;
+  id   |           abort_increasing           |           abort_decreasing           |          noabort_increasing          |          noabort_decreasing          
+-------+--------------------------------------+--------------------------------------+--------------------------------------+--------------------------------------
+ 20010 | 00000000-0000-0000-0000-000000020000 | 00000000-0000-0000-0000-000000000000 | 00009991-0000-0000-0000-000000020000 | 00000000-0000-0000-0000-000000000000
+ 20001 | 00000000-0000-0000-0000-000000020000 | 00000000-0000-0000-0000-000000000000 | 00009991-0000-0000-0000-000000020000 | 00000000-0000-0000-0000-000000000000
+  9992 | 00000000-0000-0000-0000-000000009991 | 00000000-0000-0000-0000-000000010009 | 00009991-0000-0000-0000-000000009991 | 00000000-0000-0000-0000-000000010009
+ 20000 | 00000000-0000-0000-0000-000000019999 | 00000000-0000-0000-0000-000000000001 | 00009990-0000-0000-0000-000000019999 | 00000001-0000-0000-0000-000000000001
+  9991 | 00000000-0000-0000-0000-000000009990 | 00000000-0000-0000-0000-000000010010 | 00009990-0000-0000-0000-000000009990 | 00000001-0000-0000-0000-000000010010
+(5 rows)
+
+-- tail
+SELECT id, abort_increasing, abort_decreasing, noabort_increasing, noabort_decreasing
+FROM abbrev_abort_uuids
+ORDER BY ctid DESC LIMIT 5;
+  id   |           abort_increasing           |           abort_decreasing           |          noabort_increasing          |          noabort_decreasing          
+-------+--------------------------------------+--------------------------------------+--------------------------------------+--------------------------------------
+     0 |                                      |                                      |                                      | 
+ 20003 |                                      |                                      |                                      | 
+ 20002 |                                      |                                      |                                      | 
+  9993 | 00000000-0000-0000-0000-000000009992 | 00000000-0000-0000-0000-000000010008 | 00009992-0000-0000-0000-000000009992 | 00010008-0000-0000-0000-000000010008
+  9994 | 00000000-0000-0000-0000-000000009993 | 00000000-0000-0000-0000-000000010007 | 00009993-0000-0000-0000-000000009993 | 00010007-0000-0000-0000-000000010007
+(5 rows)
+
+ROLLBACK;
+----
+-- test forward and backward scans for in-memory and disk based tuplesort
+----
+-- in-memory
+BEGIN;
+SET LOCAL enable_indexscan = false;
+-- unfortunately can't show analyze output confirming sort method,
+-- the memory used output wouldn't be stable
+EXPLAIN (COSTS OFF) DECLARE c SCROLL CURSOR FOR SELECT noabort_decreasing FROM abbrev_abort_uuids ORDER BY noabort_decreasing;
+              QUERY PLAN              
+--------------------------------------
+ Sort
+   Sort Key: noabort_decreasing
+   ->  Seq Scan on abbrev_abort_uuids
+(3 rows)
+
+DECLARE c SCROLL CURSOR FOR SELECT noabort_decreasing FROM abbrev_abort_uuids ORDER BY noabort_decreasing;
+-- first and second
+FETCH NEXT FROM c;
+          noabort_decreasing          
+--------------------------------------
+ 00000000-0000-0000-0000-000000000000
+(1 row)
+
+FETCH NEXT FROM c;
+          noabort_decreasing          
+--------------------------------------
+ 00000000-0000-0000-0000-000000000000
+(1 row)
+
+-- scroll beyond beginning
+FETCH BACKWARD FROM c;
+          noabort_decreasing          
+--------------------------------------
+ 00000000-0000-0000-0000-000000000000
+(1 row)
+
+FETCH BACKWARD FROM c;
+ noabort_decreasing 
+--------------------
+(0 rows)
+
+FETCH BACKWARD FROM c;
+ noabort_decreasing 
+--------------------
+(0 rows)
+
+FETCH BACKWARD FROM c;
+ noabort_decreasing 
+--------------------
+(0 rows)
+
+FETCH NEXT FROM c;
+          noabort_decreasing          
+--------------------------------------
+ 00000000-0000-0000-0000-000000000000
+(1 row)
+
+-- scroll beyond end end
+FETCH LAST FROM c;
+ noabort_decreasing 
+--------------------
+ 
+(1 row)
+
+FETCH BACKWARD FROM c;
+ noabort_decreasing 
+--------------------
+ 
+(1 row)
+
+FETCH NEXT FROM c;
+ noabort_decreasing 
+--------------------
+ 
+(1 row)
+
+FETCH NEXT FROM c;
+ noabort_decreasing 
+--------------------
+(0 rows)
+
+FETCH NEXT FROM c;
+ noabort_decreasing 
+--------------------
+(0 rows)
+
+FETCH BACKWARD FROM c;
+ noabort_decreasing 
+--------------------
+ 
+(1 row)
+
+FETCH NEXT FROM c;
+ noabort_decreasing 
+--------------------
+(0 rows)
+
+COMMIT;
+-- disk based
+BEGIN;
+SET LOCAL enable_indexscan = false;
+SET LOCAL work_mem = '100kB';
+-- unfortunately can't show analyze output confirming sort method,
+-- the memory used output wouldn't be stable
+EXPLAIN (COSTS OFF) DECLARE c SCROLL CURSOR FOR SELECT noabort_decreasing FROM abbrev_abort_uuids ORDER BY noabort_decreasing;
+              QUERY PLAN              
+--------------------------------------
+ Sort
+   Sort Key: noabort_decreasing
+   ->  Seq Scan on abbrev_abort_uuids
+(3 rows)
+
+DECLARE c SCROLL CURSOR FOR SELECT noabort_decreasing FROM abbrev_abort_uuids ORDER BY noabort_decreasing;
+-- first and second
+FETCH NEXT FROM c;
+          noabort_decreasing          
+--------------------------------------
+ 00000000-0000-0000-0000-000000000000
+(1 row)
+
+FETCH NEXT FROM c;
+          noabort_decreasing          
+--------------------------------------
+ 00000000-0000-0000-0000-000000000000
+(1 row)
+
+-- scroll beyond beginning
+FETCH BACKWARD FROM c;
+          noabort_decreasing          
+--------------------------------------
+ 00000000-0000-0000-0000-000000000000
+(1 row)
+
+FETCH BACKWARD FROM c;
+ noabort_decreasing 
+--------------------
+(0 rows)
+
+FETCH BACKWARD FROM c;
+ noabort_decreasing 
+--------------------
+(0 rows)
+
+FETCH BACKWARD FROM c;
+ noabort_decreasing 
+--------------------
+(0 rows)
+
+FETCH NEXT FROM c;
+          noabort_decreasing          
+--------------------------------------
+ 00000000-0000-0000-0000-000000000000
+(1 row)
+
+-- scroll beyond end end
+FETCH LAST FROM c;
+ noabort_decreasing 
+--------------------
+ 
+(1 row)
+
+FETCH BACKWARD FROM c;
+ noabort_decreasing 
+--------------------
+ 
+(1 row)
+
+FETCH NEXT FROM c;
+ noabort_decreasing 
+--------------------
+ 
+(1 row)
+
+FETCH NEXT FROM c;
+ noabort_decreasing 
+--------------------
+(0 rows)
+
+FETCH NEXT FROM c;
+ noabort_decreasing 
+--------------------
+(0 rows)
+
+FETCH BACKWARD FROM c;
+ noabort_decreasing 
+--------------------
+ 
+(1 row)
+
+FETCH NEXT FROM c;
+ noabort_decreasing 
+--------------------
+(0 rows)
+
+COMMIT;
+----
+-- test tuplesort using both in-memory and disk sort
+---
+-- memory based
+SELECT
+    -- fixed-width by-value datum
+    (array_agg(id ORDER BY id DESC NULLS FIRST))[0:5],
+    -- fixed-width by-ref datum
+    (array_agg(abort_increasing ORDER BY abort_increasing DESC NULLS LAST))[0:5],
+    -- variable-width datum
+    (array_agg(id::text ORDER BY id::text DESC NULLS LAST))[0:5],
+    -- fixed width by-value datum tuplesort
+    percentile_disc(0.99) WITHIN GROUP (ORDER BY id),
+    -- ensure state is shared
+    percentile_disc(0.01) WITHIN GROUP (ORDER BY id),
+    -- fixed width by-ref datum tuplesort
+    percentile_disc(0.8) WITHIN GROUP (ORDER BY abort_increasing),
+    -- variable width by-ref datum tuplesort
+    percentile_disc(0.2) WITHIN GROUP (ORDER BY id::text),
+    -- multi-column tuplesort
+    rank('00000000-0000-0000-0000-000000000000', '2', '2') WITHIN GROUP (ORDER BY noabort_increasing, id, id::text)
+FROM (
+    SELECT * FROM abbrev_abort_uuids
+    UNION ALL
+    SELECT NULL, NULL, NULL, NULL, NULL) s;
+           array_agg            |                                                                                         array_agg                                                                                          |         array_agg          | percentile_disc | percentile_disc |           percentile_disc            | percentile_disc | rank 
+--------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------------+-----------------+-----------------+--------------------------------------+-----------------+------
+ {NULL,20010,20009,20008,20007} | {00000000-0000-0000-0000-000000020000,00000000-0000-0000-0000-000000020000,00000000-0000-0000-0000-000000019999,00000000-0000-0000-0000-000000019998,00000000-0000-0000-0000-000000019997} | {9999,9998,9997,9996,9995} |           19810 |             200 | 00000000-0000-0000-0000-000000016003 | 136             |    2
+(1 row)
+
+-- disk based (see also above)
+BEGIN;
+SET LOCAL work_mem = '100kB';
+SELECT
+    (array_agg(id ORDER BY id DESC NULLS FIRST))[0:5],
+    (array_agg(abort_increasing ORDER BY abort_increasing DESC NULLS LAST))[0:5],
+    (array_agg(id::text ORDER BY id::text DESC NULLS LAST))[0:5],
+    percentile_disc(0.99) WITHIN GROUP (ORDER BY id),
+    percentile_disc(0.01) WITHIN GROUP (ORDER BY id),
+    percentile_disc(0.8) WITHIN GROUP (ORDER BY abort_increasing),
+    percentile_disc(0.2) WITHIN GROUP (ORDER BY id::text),
+    rank('00000000-0000-0000-0000-000000000000', '2', '2') WITHIN GROUP (ORDER BY noabort_increasing, id, id::text)
+FROM (
+    SELECT * FROM abbrev_abort_uuids
+    UNION ALL
+    SELECT NULL, NULL, NULL, NULL, NULL) s;
+           array_agg            |                                                                                         array_agg                                                                                          |         array_agg          | percentile_disc | percentile_disc |           percentile_disc            | percentile_disc | rank 
+--------------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------------+-----------------+-----------------+--------------------------------------+-----------------+------
+ {NULL,20010,20009,20008,20007} | {00000000-0000-0000-0000-000000020000,00000000-0000-0000-0000-000000020000,00000000-0000-0000-0000-000000019999,00000000-0000-0000-0000-000000019998,00000000-0000-0000-0000-000000019997} | {9999,9998,9997,9996,9995} |           19810 |             200 | 00000000-0000-0000-0000-000000016003 | 136             |    2
+(1 row)
+
+ROLLBACK;
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index fc0f14122bb..d33a4e143dc 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -112,7 +112,7 @@ test: plancache limit plpgsql copy2 temp domain rangefuncs prepare conversion tr
 # ----------
 # Another group of parallel tests
 # ----------
-test: partition_join partition_prune reloptions hash_part indexing partition_aggregate partition_info
+test: partition_join partition_prune reloptions hash_part indexing partition_aggregate partition_info tuplesort
 
 # event triggers cannot run concurrently with any test that runs DDL
 test: event_trigger
diff --git a/src/test/regress/sql/tuplesort.sql b/src/test/regress/sql/tuplesort.sql
new file mode 100644
index 00000000000..ad47dd3168f
--- /dev/null
+++ b/src/test/regress/sql/tuplesort.sql
@@ -0,0 +1,258 @@
+-- only use parallelism when explicitly intending to do so
+SET max_parallel_maintenance_workers = 0;
+SET max_parallel_workers = 0;
+
+-- A table with with contents that, when sorted, triggers abbreviated
+-- key aborts. One easy way to achieve that is to use uuids that all
+-- have the same prefix, as abbreviated keys for uuids just use the
+-- first sizeof(Datum) bytes.
+DROP TABLE IF EXISTS abbrev_abort_uuids;
+
+CREATE TABLE abbrev_abort_uuids (
+    id serial not null,
+    abort_increasing uuid,
+    abort_decreasing uuid,
+    noabort_increasing uuid,
+    noabort_decreasing uuid);
+
+INSERT INTO abbrev_abort_uuids (abort_increasing, abort_decreasing, noabort_increasing, noabort_decreasing)
+    SELECT
+        ('00000000-0000-0000-0000-'||to_char(g.i, '000000000000FM'))::uuid abort_increasing,
+        ('00000000-0000-0000-0000-'||to_char(20000 - g.i, '000000000000FM'))::uuid abort_decreasing,
+        (to_char(g.i % 10009, '00000000FM')||'-0000-0000-0000-'||to_char(g.i, '000000000000FM'))::uuid noabort_increasing,
+        (to_char(((20000 - g.i) % 10009), '00000000FM')||'-0000-0000-0000-'||to_char(20000 - g.i, '000000000000FM'))::uuid noabort_decreasing
+    FROM generate_series(0, 20000, 1) g(i);
+
+-- and a few NULLs
+INSERT INTO abbrev_abort_uuids(id) VALUES(0);
+INSERT INTO abbrev_abort_uuids DEFAULT VALUES;
+INSERT INTO abbrev_abort_uuids DEFAULT VALUES;
+
+-- add just a few duplicates
+INSERT INTO abbrev_abort_uuids (abort_increasing, abort_decreasing, noabort_increasing, noabort_decreasing)
+    SELECT abort_increasing, abort_decreasing, noabort_increasing, noabort_decreasing
+    FROM abbrev_abort_uuids
+    WHERE (id < 10 OR id > 19990) AND id % 3 = 0 AND abort_increasing is not null;
+
+----
+-- Check sort node uses of tuplesort wrt. abbreviated keys
+----
+
+-- plain sort triggering abbreviated abort
+SELECT abort_increasing, abort_decreasing FROM abbrev_abort_uuids ORDER BY abort_increasing OFFSET 20000 - 4;
+SELECT abort_increasing, abort_decreasing FROM abbrev_abort_uuids ORDER BY abort_decreasing NULLS FIRST OFFSET 20000 - 4;
+
+-- plain sort not triggering abbreviated abort
+SELECT noabort_increasing, noabort_decreasing FROM abbrev_abort_uuids ORDER BY noabort_increasing OFFSET 20000 - 4;
+SELECT noabort_increasing, noabort_decreasing FROM abbrev_abort_uuids ORDER BY noabort_decreasing NULLS FIRST OFFSET 20000 - 4;
+
+-- bounded sort (disables abbreviated keys)
+SELECT abort_increasing, noabort_increasing FROM abbrev_abort_uuids ORDER BY abort_increasing LIMIT 5;
+SELECT abort_increasing, noabort_increasing FROM abbrev_abort_uuids ORDER BY noabort_increasing NULLS FIRST LIMIT 5;
+
+
+----
+-- Check index creation uses of tuplesort wrt. abbreviated keys
+----
+
+-- index creation using abbreviated keys successfully
+CREATE INDEX abbrev_abort_uuids__noabort_increasing_idx ON abbrev_abort_uuids (noabort_increasing);
+CREATE INDEX abbrev_abort_uuids__noabort_decreasing_idx ON abbrev_abort_uuids (noabort_decreasing);
+
+-- verify
+EXPLAIN SELECT id, noabort_increasing, noabort_decreasing FROM abbrev_abort_uuids ORDER BY noabort_increasing LIMIT 5;
+SELECT id, noabort_increasing, noabort_decreasing FROM abbrev_abort_uuids ORDER BY noabort_increasing LIMIT 5;
+EXPLAIN SELECT id, noabort_increasing, noabort_decreasing FROM abbrev_abort_uuids ORDER BY noabort_decreasing LIMIT 5;
+SELECT id, noabort_increasing, noabort_decreasing FROM abbrev_abort_uuids ORDER BY noabort_decreasing LIMIT 5;
+
+-- index creation using abbreviated keys, hitting abort
+CREATE INDEX abbrev_abort_uuids__abort_increasing_idx ON abbrev_abort_uuids (abort_increasing);
+CREATE INDEX abbrev_abort_uuids__abort_decreasing_idx ON abbrev_abort_uuids (abort_decreasing);
+
+-- verify
+EXPLAIN SELECT id, abort_increasing, abort_decreasing FROM abbrev_abort_uuids ORDER BY abort_increasing LIMIT 5;
+SELECT id, abort_increasing, abort_decreasing FROM abbrev_abort_uuids ORDER BY abort_increasing LIMIT 5;
+EXPLAIN SELECT id, abort_increasing, abort_decreasing FROM abbrev_abort_uuids ORDER BY abort_decreasing LIMIT 5;
+SELECT id, abort_increasing, abort_decreasing FROM abbrev_abort_uuids ORDER BY abort_decreasing LIMIT 5;
+
+
+----
+-- Check CLUSTER uses of tuplesort wrt. abbreviated keys
+----
+
+-- when aborting, increasing order
+BEGIN;
+SET LOCAL enable_indexscan = false;
+CLUSTER abbrev_abort_uuids USING abbrev_abort_uuids__abort_increasing_idx;
+
+-- head
+SELECT id, abort_increasing, abort_decreasing, noabort_increasing, noabort_decreasing
+FROM abbrev_abort_uuids
+ORDER BY ctid LIMIT 5;
+
+-- tail
+SELECT id, abort_increasing, abort_decreasing, noabort_increasing, noabort_decreasing
+FROM abbrev_abort_uuids
+ORDER BY ctid DESC LIMIT 5;
+ROLLBACK;
+
+-- when aborting, decreasing order
+BEGIN;
+SET LOCAL enable_indexscan = false;
+CLUSTER abbrev_abort_uuids USING abbrev_abort_uuids__abort_decreasing_idx;
+
+-- head
+SELECT id, abort_increasing, abort_decreasing, noabort_increasing, noabort_decreasing
+FROM abbrev_abort_uuids
+ORDER BY ctid LIMIT 5;
+
+-- tail
+SELECT id, abort_increasing, abort_decreasing, noabort_increasing, noabort_decreasing
+FROM abbrev_abort_uuids
+ORDER BY ctid DESC LIMIT 5;
+ROLLBACK;
+
+-- when not aborting, increasing order
+BEGIN;
+SET LOCAL enable_indexscan = false;
+CLUSTER abbrev_abort_uuids USING abbrev_abort_uuids__noabort_increasing_idx;
+
+-- head
+SELECT id, abort_increasing, abort_decreasing, noabort_increasing, noabort_decreasing
+FROM abbrev_abort_uuids
+ORDER BY ctid LIMIT 5;
+
+-- tail
+SELECT id, abort_increasing, abort_decreasing, noabort_increasing, noabort_decreasing
+FROM abbrev_abort_uuids
+ORDER BY ctid DESC LIMIT 5;
+ROLLBACK;
+
+-- when no aborting, decreasing order
+BEGIN;
+SET LOCAL enable_indexscan = false;
+CLUSTER abbrev_abort_uuids USING abbrev_abort_uuids__noabort_decreasing_idx;
+
+-- head
+SELECT id, abort_increasing, abort_decreasing, noabort_increasing, noabort_decreasing
+FROM abbrev_abort_uuids
+ORDER BY ctid LIMIT 5;
+
+-- tail
+SELECT id, abort_increasing, abort_decreasing, noabort_increasing, noabort_decreasing
+FROM abbrev_abort_uuids
+ORDER BY ctid DESC LIMIT 5;
+ROLLBACK;
+
+----
+-- test forward and backward scans for in-memory and disk based tuplesort
+----
+
+-- in-memory
+BEGIN;
+SET LOCAL enable_indexscan = false;
+-- unfortunately can't show analyze output confirming sort method,
+-- the memory used output wouldn't be stable
+EXPLAIN (COSTS OFF) DECLARE c SCROLL CURSOR FOR SELECT noabort_decreasing FROM abbrev_abort_uuids ORDER BY noabort_decreasing;
+DECLARE c SCROLL CURSOR FOR SELECT noabort_decreasing FROM abbrev_abort_uuids ORDER BY noabort_decreasing;
+
+-- first and second
+FETCH NEXT FROM c;
+FETCH NEXT FROM c;
+
+-- scroll beyond beginning
+FETCH BACKWARD FROM c;
+FETCH BACKWARD FROM c;
+FETCH BACKWARD FROM c;
+FETCH BACKWARD FROM c;
+FETCH NEXT FROM c;
+
+-- scroll beyond end end
+FETCH LAST FROM c;
+FETCH BACKWARD FROM c;
+FETCH NEXT FROM c;
+FETCH NEXT FROM c;
+FETCH NEXT FROM c;
+FETCH BACKWARD FROM c;
+FETCH NEXT FROM c;
+
+COMMIT;
+
+-- disk based
+BEGIN;
+SET LOCAL enable_indexscan = false;
+SET LOCAL work_mem = '100kB';
+-- unfortunately can't show analyze output confirming sort method,
+-- the memory used output wouldn't be stable
+EXPLAIN (COSTS OFF) DECLARE c SCROLL CURSOR FOR SELECT noabort_decreasing FROM abbrev_abort_uuids ORDER BY noabort_decreasing;
+DECLARE c SCROLL CURSOR FOR SELECT noabort_decreasing FROM abbrev_abort_uuids ORDER BY noabort_decreasing;
+
+-- first and second
+FETCH NEXT FROM c;
+FETCH NEXT FROM c;
+
+-- scroll beyond beginning
+FETCH BACKWARD FROM c;
+FETCH BACKWARD FROM c;
+FETCH BACKWARD FROM c;
+FETCH BACKWARD FROM c;
+FETCH NEXT FROM c;
+
+-- scroll beyond end end
+FETCH LAST FROM c;
+FETCH BACKWARD FROM c;
+FETCH NEXT FROM c;
+FETCH NEXT FROM c;
+FETCH NEXT FROM c;
+FETCH BACKWARD FROM c;
+FETCH NEXT FROM c;
+
+COMMIT;
+
+
+----
+-- test tuplesort using both in-memory and disk sort
+---
+
+-- memory based
+SELECT
+    -- fixed-width by-value datum
+    (array_agg(id ORDER BY id DESC NULLS FIRST))[0:5],
+    -- fixed-width by-ref datum
+    (array_agg(abort_increasing ORDER BY abort_increasing DESC NULLS LAST))[0:5],
+    -- variable-width datum
+    (array_agg(id::text ORDER BY id::text DESC NULLS LAST))[0:5],
+    -- fixed width by-value datum tuplesort
+    percentile_disc(0.99) WITHIN GROUP (ORDER BY id),
+    -- ensure state is shared
+    percentile_disc(0.01) WITHIN GROUP (ORDER BY id),
+    -- fixed width by-ref datum tuplesort
+    percentile_disc(0.8) WITHIN GROUP (ORDER BY abort_increasing),
+    -- variable width by-ref datum tuplesort
+    percentile_disc(0.2) WITHIN GROUP (ORDER BY id::text),
+    -- multi-column tuplesort
+    rank('00000000-0000-0000-0000-000000000000', '2', '2') WITHIN GROUP (ORDER BY noabort_increasing, id, id::text)
+FROM (
+    SELECT * FROM abbrev_abort_uuids
+    UNION ALL
+    SELECT NULL, NULL, NULL, NULL, NULL) s;
+
+-- disk based (see also above)
+BEGIN;
+SET LOCAL work_mem = '100kB';
+
+SELECT
+    (array_agg(id ORDER BY id DESC NULLS FIRST))[0:5],
+    (array_agg(abort_increasing ORDER BY abort_increasing DESC NULLS LAST))[0:5],
+    (array_agg(id::text ORDER BY id::text DESC NULLS LAST))[0:5],
+    percentile_disc(0.99) WITHIN GROUP (ORDER BY id),
+    percentile_disc(0.01) WITHIN GROUP (ORDER BY id),
+    percentile_disc(0.8) WITHIN GROUP (ORDER BY abort_increasing),
+    percentile_disc(0.2) WITHIN GROUP (ORDER BY id::text),
+    rank('00000000-0000-0000-0000-000000000000', '2', '2') WITHIN GROUP (ORDER BY noabort_increasing, id, id::text)
+FROM (
+    SELECT * FROM abbrev_abort_uuids
+    UNION ALL
+    SELECT NULL, NULL, NULL, NULL, NULL) s;
+
+ROLLBACK;
-- 
2.23.0.385.gbc12974a89

