upstream/postgresql
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2026-05-28 04:35:45 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

Fix REPACK with WITHOUT OVERLAPS replica identity indexes

Browse source 
REPACK replay builds scan keys for the replica identity index, but it
hard-coded BTEqualStrategyNumber when looking up the equality operator.
That is not correct for non-btree identity indexes, such as the GiST
indexes created for WITHOUT OVERLAPS primary keys.  In addition,
find_target_tuple() accepted the first tuple returned by the identity
index scan, which is unsafe for lossy index scans because the index AM may
return false positives with xs_recheck set.

Fix this by using IndexAmTranslateCompareType() to translate COMPARE_EQ
to the equality strategy number for the index AM, and by continuing the
scan when recheck is required until a candidate tuple matches the locator
tuple on all replica identity key columns.

The recheck uses the same equality operator functions as the identity
index scan keys, preserving ScanKey argument ordering.

Author: Chao Li <lic@highgo.com>
Reviewed-by: Kirill Reshke <reshkekirill@gmail.com>
Reviewed-by: Álvaro Herrera <alvherre@kurilemu.de>
Discussion: https://postgr.es/m/7B0EC0EC-5461-41EF-9B31-F9BBE608DEA5@gmail.com
This commit is contained in:
Álvaro Herrera 2026-05-11 18:17:46 +02:00
parent 906ea101d0
commit 36f52a59b3
No known key found for this signature in database
GPG key ID: 1C20ACB9D5C564AE
7 changed files with 417 additions and 6 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

85
src/backend/commands/repack.c
View file

@ -118,6 +118,9 @@ typedef struct ChangeContext
ScanKey cc_ident_key;
int cc_ident_key_nentries;
/* The latest column we need to deform to have the tuple identity */
AttrNumber cc_last_key_attno;
/* Sequential number of the file containing the changes. */
int cc_file_seq;
} ChangeContext;
@ -182,6 +185,9 @@ static void adjust_toast_pointers(Relation relation, TupleTableSlot *dest,
static bool find_target_tuple(Relation rel, ChangeContext *chgcxt,
TupleTableSlot *locator,
TupleTableSlot *retrieved);
static bool identity_key_equal(ChangeContext *chgcxt,
TupleTableSlot *locator,
TupleTableSlot *candidate);
static void process_concurrent_changes(XLogRecPtr end_of_wal,
ChangeContext *chgcxt,
bool done);
@ -2807,7 +2813,7 @@ find_target_tuple(Relation rel, ChangeContext *chgcxt, TupleTableSlot *locator,
{
Form_pg_index idx = chgcxt->cc_ident_index->rd_index;
IndexScanDesc scan;
bool retval;
bool retval = false;
/*
* Scan key is passed by caller, so it does not have to be constructed
@ -2829,12 +2835,61 @@ find_target_tuple(Relation rel, ChangeContext *chgcxt, TupleTableSlot *locator,
scan = index_beginscan(rel, chgcxt->cc_ident_index, GetActiveSnapshot(),
NULL, chgcxt->cc_ident_key_nentries, 0, 0);
index_rescan(scan, chgcxt->cc_ident_key, chgcxt->cc_ident_key_nentries, NULL, 0);
retval = index_getnext_slot(scan, ForwardScanDirection, retrieved);
while (index_getnext_slot(scan, ForwardScanDirection, retrieved))
{
/* Be wary of temporal constraints */
if (scan->xs_recheck && !identity_key_equal(chgcxt, locator, retrieved))
{
CHECK_FOR_INTERRUPTS();
continue;
}
retval = true;
break;
}
index_endscan(scan);
return retval;
}
/*
* Check whether the candidate tuple matches the locator tuple on all replica
* identity key columns, using the same equality operators as the identity
* index scan. The locator tuple has already been loaded into cc_ident_key.
*
* This is needed to filter lossy index matches, such as GiST multirange scans
* used for temporal constraints.
*/
static bool
identity_key_equal(ChangeContext *chgcxt, TupleTableSlot *locator,
TupleTableSlot *candidate)
{
slot_getsomeattrs(locator, chgcxt->cc_last_key_attno);
slot_getsomeattrs(candidate, chgcxt->cc_last_key_attno);
for (int i = 0; i < chgcxt->cc_ident_key_nentries; i++)
{
ScanKey entry = &chgcxt->cc_ident_key[i];
AttrNumber attno = chgcxt->cc_ident_index->rd_index->indkey.values[i];
Assert(attno > 0);
if (locator->tts_isnull[attno - 1] != candidate->tts_isnull[attno - 1])
return false;
if (locator->tts_isnull[attno - 1])
continue;
if (!DatumGetBool(FunctionCall2Coll(&entry->sk_func,
entry->sk_collation,
candidate->tts_values[attno - 1],
entry->sk_argument)))
return false;
}
return true;
}
/*
* Decode and apply concurrent changes, up to (and including) the record whose
* LSN is 'end_of_wal'.
@ -2944,28 +2999,46 @@ initialize_change_context(ChangeContext *chgcxt,
opcintype,
opno,
opcode;
StrategyNumber eq_strategy;
entry = &chgcxt->cc_ident_key[i];
opfamily = chgcxt->cc_ident_index->rd_opfamily[i];
opcintype = chgcxt->cc_ident_index->rd_opcintype[i];
eq_strategy = IndexAmTranslateCompareType(COMPARE_EQ,
chgcxt->cc_ident_index->rd_rel->relam,
opfamily, false);
if (eq_strategy == InvalidStrategy)
elog(ERROR, "could not find equality strategy for index operator family %u for type %u",
opfamily, opcintype);
opno = get_opfamily_member(opfamily, opcintype, opcintype,
BTEqualStrategyNumber);
eq_strategy);
if (!OidIsValid(opno))
elog(ERROR, "failed to find = operator for type %u", opcintype);
elog(ERROR, "missing operator %d(%u,%u) in opfamily %u",
eq_strategy, opcintype, opcintype, opfamily);
opcode = get_opcode(opno);
if (!OidIsValid(opcode))
elog(ERROR, "failed to find = operator for operator %u", opno);
elog(ERROR, "missing oprcode for operator %u", opno);
/* Initialize everything but argument. */
ScanKeyInit(entry,
i + 1,
BTEqualStrategyNumber, opcode,
eq_strategy, opcode,
(Datum) 0);
entry->sk_collation = chgcxt->cc_ident_index->rd_indcollation[i];
}
}
/* Determine the last column we must deform to read the identity */
chgcxt->cc_last_key_attno = InvalidAttrNumber;
for (int i = 0; i < chgcxt->cc_ident_key_nentries; i++)
{
AttrNumber attno = chgcxt->cc_ident_index->rd_index->indkey.values[i];
Assert(attno > 0);
chgcxt->cc_last_key_attno = Max(chgcxt->cc_last_key_attno, attno);
}
chgcxt->cc_file_seq = WORKER_FILE_SNAPSHOT + 1;
}

2
src/test/modules/injection_points/Makefile
View file

@ -15,6 +15,8 @@ REGRESS_OPTS = --dlpath=$(top_builddir)/src/test/regress
ISOLATION = basic \
inplace \
repack \
repack_temporal \
repack_temporal_multirange \
repack_toast \
syscache-update-pruned \
heap_lock_update

68
src/test/modules/injection_points/expected/repack_temporal.out Normal file
View file

@ -0,0 +1,68 @@
Parsed test spec with 2 sessions
starting permutation: wait_before_lock update_target check_after_update wakeup_before_lock check_after_repack
injection_points_attach
-----------------------
(1 row)
step wait_before_lock:
REPACK (CONCURRENTLY) repack_temporal USING INDEX rt_pkey;
<waiting ...>
step update_target:
UPDATE repack_temporal
SET label = 'updated'
WHERE id = '[2,3)' AND valid_at = '[2000-01-10,2000-01-20)';
step check_after_update:
INSERT INTO relfilenodes(node)
SELECT relfilenode FROM pg_class WHERE relname = 'repack_temporal';
-- Expect 2 rows
SELECT id, valid_at, label
FROM repack_temporal
ORDER BY id, valid_at, label;
id |valid_at |label
------+-----------------------+-------
[1,10)|[01-01-2000,02-01-2000)|other
[2,3) |[01-10-2000,01-20-2000)|updated
(2 rows)
step wakeup_before_lock:
SELECT injection_points_wakeup('repack-concurrently-before-lock');
injection_points_wakeup
-----------------------
(1 row)
step wait_before_lock: <... completed>
step check_after_repack:
INSERT INTO relfilenodes(node)
SELECT relfilenode FROM pg_class WHERE relname = 'repack_temporal';
-- Expect 2, proving that repack has rewritten the table
SELECT count(DISTINCT node) FROM relfilenodes;
-- Expect 2 rows
SELECT id, valid_at, label
FROM repack_temporal
ORDER BY id, valid_at, label;
count
-----
2
(1 row)
id |valid_at |label
------+-----------------------+-------
[1,10)|[01-01-2000,02-01-2000)|other
[2,3) |[01-10-2000,01-20-2000)|updated
(2 rows)
injection_points_detach
-----------------------
(1 row)

74
src/test/modules/injection_points/expected/repack_temporal_multirange.out Normal file
View file

@ -0,0 +1,74 @@
Parsed test spec with 2 sessions
starting permutation: wait_before_lock update_target check_after_update wakeup_before_lock final_check
injection_points_attach
-----------------------
(1 row)
step wait_before_lock:
REPACK (CONCURRENTLY) repack_temporal_multirange
USING INDEX rtm_pkey;
<waiting ...>
step update_target:
UPDATE repack_temporal_multirange
SET label = 'updated'
WHERE id = int4multirange(int4range(1, 7))
AND valid_at = datemultirange(daterange('2000-01-01', '2000-02-01'));
step check_after_update:
INSERT INTO relfilenodes(node)
SELECT relfilenode
FROM pg_class
WHERE relname = 'repack_temporal_multirange';
-- Expect 2 rows
SELECT id, valid_at, label
FROM repack_temporal_multirange
ORDER BY id, valid_at, label;
id |valid_at |label
-------------+-------------------------+-------
{[1,3),[5,7)}|{[01-01-2000,02-01-2000)}|other
{[1,7)} |{[01-01-2000,02-01-2000)}|updated
(2 rows)
step wakeup_before_lock:
SELECT injection_points_wakeup('repack-concurrently-before-lock');
injection_points_wakeup
-----------------------
(1 row)
step wait_before_lock: <... completed>
step final_check:
INSERT INTO relfilenodes(node)
SELECT relfilenode
FROM pg_class
WHERE relname = 'repack_temporal_multirange';
-- Expect 2, proving that repack has rewritten the table
SELECT count(DISTINCT node) FROM relfilenodes;
-- Expect 2 rows
SELECT id, valid_at, label
FROM repack_temporal_multirange
ORDER BY id, valid_at, label;
count
-----
2
(1 row)
id |valid_at |label
-------------+-------------------------+-------
{[1,3),[5,7)}|{[01-01-2000,02-01-2000)}|other
{[1,7)} |{[01-01-2000,02-01-2000)}|updated
(2 rows)
injection_points_detach
-----------------------
(1 row)

2
src/test/modules/injection_points/meson.build
View file

@ -46,6 +46,8 @@ tests += {
'basic',
'inplace',
'repack',
'repack_temporal',
'repack_temporal_multirange',
'repack_toast',
'syscache-update-pruned',
'heap_lock_update',

90
src/test/modules/injection_points/specs/repack_temporal.spec Normal file
View file

@ -0,0 +1,90 @@
# REPACK (CONCURRENTLY) on a temporal replica identity index.
#
# The table's replica identity is a GiST index created by a temporal primary
# key. A concurrent UPDATE changes a non-key column of one row, while another
# row overlaps it on all indexed columns. Replay must still find the exact
# target row.
setup
{
CREATE EXTENSION injection_points;
CREATE TABLE repack_temporal (
id int4range,
valid_at daterange,
label text,
CONSTRAINT rt_pkey PRIMARY KEY (id, valid_at WITHOUT OVERLAPS)
);
ALTER TABLE repack_temporal REPLICA IDENTITY USING INDEX rt_pkey;
INSERT INTO repack_temporal(id, valid_at, label)
VALUES
('[1,10)', '[2000-01-01,2000-02-01)', 'other'),
('[2,3)', '[2000-01-10,2000-01-20)', 'target');
CREATE TABLE relfilenodes(node oid);
}
teardown
{
DROP TABLE repack_temporal;
DROP EXTENSION injection_points;
DROP TABLE relfilenodes;
}
session s1
setup
{
SELECT injection_points_set_local();
SELECT injection_points_attach('repack-concurrently-before-lock', 'wait');
}
step wait_before_lock
{
REPACK (CONCURRENTLY) repack_temporal USING INDEX rt_pkey;
}
step check_after_repack
{
INSERT INTO relfilenodes(node)
SELECT relfilenode FROM pg_class WHERE relname = 'repack_temporal';
-- Expect 2, proving that repack has rewritten the table
SELECT count(DISTINCT node) FROM relfilenodes;
-- Expect 2 rows
SELECT id, valid_at, label
FROM repack_temporal
ORDER BY id, valid_at, label;
}
teardown
{
SELECT injection_points_detach('repack-concurrently-before-lock');
}
session s2
step update_target
{
UPDATE repack_temporal
SET label = 'updated'
WHERE id = '[2,3)' AND valid_at = '[2000-01-10,2000-01-20)';
}
step check_after_update
{
INSERT INTO relfilenodes(node)
SELECT relfilenode FROM pg_class WHERE relname = 'repack_temporal';
-- Expect 2 rows
SELECT id, valid_at, label
FROM repack_temporal
ORDER BY id, valid_at, label;
}
step wakeup_before_lock
{
SELECT injection_points_wakeup('repack-concurrently-before-lock');
}
permutation
wait_before_lock
update_target
check_after_update
wakeup_before_lock
check_after_repack

102
src/test/modules/injection_points/specs/repack_temporal_multirange.spec Normal file
View file

@ -0,0 +1,102 @@
# REPACK (CONCURRENTLY) on a temporal replica identity index with lossy
# multirange equality.
#
# The leading identity column is of type int4multirange. Two distinct rows
# have different multirange values but the same union range, so GiST equality
# can produce both as candidates and requires exact recheck.
setup
{
CREATE EXTENSION injection_points;
CREATE TABLE repack_temporal_multirange (
id int4multirange,
valid_at datemultirange,
label text,
CONSTRAINT rtm_pkey PRIMARY KEY (id, valid_at WITHOUT OVERLAPS)
);
ALTER TABLE repack_temporal_multirange
REPLICA IDENTITY USING INDEX rtm_pkey;
-- (1,3)+(5,7) is the same union range of (1-7), but needs recheck
INSERT INTO repack_temporal_multirange(id, valid_at, label)
VALUES
(int4multirange(int4range(1, 3), int4range(5, 7)),
datemultirange(daterange('2000-01-01', '2000-02-01')),
'other'),
(int4multirange(int4range(1, 7)),
datemultirange(daterange('2000-01-01', '2000-02-01')),
'target');
CREATE TABLE relfilenodes(node oid);
}
teardown
{
DROP TABLE repack_temporal_multirange;
DROP EXTENSION injection_points;
DROP TABLE relfilenodes;
}
session s1
setup
{
SELECT injection_points_set_local();
SELECT injection_points_attach('repack-concurrently-before-lock', 'wait');
}
step wait_before_lock
{
REPACK (CONCURRENTLY) repack_temporal_multirange
USING INDEX rtm_pkey;
}
step final_check
{
INSERT INTO relfilenodes(node)
SELECT relfilenode
FROM pg_class
WHERE relname = 'repack_temporal_multirange';
-- Expect 2, proving that repack has rewritten the table
SELECT count(DISTINCT node) FROM relfilenodes;
-- Expect 2 rows
SELECT id, valid_at, label
FROM repack_temporal_multirange
ORDER BY id, valid_at, label;
}
teardown
{
SELECT injection_points_detach('repack-concurrently-before-lock');
}
session s2
step update_target
{
UPDATE repack_temporal_multirange
SET label = 'updated'
WHERE id = int4multirange(int4range(1, 7))
AND valid_at = datemultirange(daterange('2000-01-01', '2000-02-01'));
}
step check_after_update
{
INSERT INTO relfilenodes(node)
SELECT relfilenode
FROM pg_class
WHERE relname = 'repack_temporal_multirange';
-- Expect 2 rows
SELECT id, valid_at, label
FROM repack_temporal_multirange
ORDER BY id, valid_at, label;
}
step wakeup_before_lock
{
SELECT injection_points_wakeup('repack-concurrently-before-lock');
}
permutation
wait_before_lock
update_target
check_after_update
wakeup_before_lock
final_check