Files
Álvaro Herrera 6350e56e5c amcheck: Fix snapshot usage in bt_index_parent_check
We were using SnapshotAny to do some index checks, but that's wrong and
causes spurious errors when used on indexes created by CREATE INDEX
CONCURRENTLY.  Fix it to use an MVCC snapshot, and add a test for it.

Backpatch of 58028308c3 to branches 14-16.  I previously misidentified
the bug's origin: it came in with commit 7f563c09f8 (pg11-era, not
80c9649c55 as claimed previously), so all live branches are affected.

Also take the opportunity to fix some comments that we failed to update
in the original commits and apply pgperltidy.  In branch 14, remove the
unnecessary test plan specification (which would have need to have been
changed anyway; c.f. commit 6e0eff53086d.)

Diagnosed-by: Donghang Lin <[email protected]>
Author: Mihail Nikalayeu <[email protected]>
Reviewed-by: Andrey Borodin <[email protected]>
Backpatch-through: 17
Discussion: https://postgr.es/m/CANtu0ojmVd27fEhfpST7RG2KZvwkX=dMyKUqg0KM87FkOSdz8Q@mail.gmail.com
2026-01-21 18:55:43 +01:00

93 lines
2.7 KiB
Perl

# Copyright (c) 2021-2026, PostgreSQL Global Development Group
# Test CREATE INDEX CONCURRENTLY with concurrent modifications
use strict;
use warnings FATAL => 'all';
use PostgreSQL::Test::Cluster;
use PostgreSQL::Test::Utils;
use Test::More;
my $node;
#
# Test set-up
#
$node = PostgreSQL::Test::Cluster->new('CIC_test');
$node->init;
$node->append_conf('postgresql.conf',
'lock_timeout = ' . (1000 * $PostgreSQL::Test::Utils::timeout_default));
$node->start;
$node->safe_psql('postgres', q(CREATE EXTENSION amcheck));
$node->safe_psql('postgres', q(CREATE TABLE tbl(i int, j jsonb)));
$node->safe_psql('postgres', q(CREATE INDEX idx ON tbl(i)));
$node->safe_psql('postgres', q(CREATE INDEX ginidx ON tbl USING gin(j)));
#
# Stress CIC with pgbench.
#
# pgbench might try to launch more than one instance of the CIC
# transaction concurrently. That would deadlock, so use an advisory
# lock to ensure only one CIC runs at a time.
#
$node->pgbench(
'--no-vacuum --client=5 --transactions=100',
0,
[qr{actually processed}],
[qr{^$}],
'concurrent INSERTs and CIC',
{
'002_pgbench_concurrent_transaction' => q(
BEGIN;
INSERT INTO tbl VALUES(0, '{"a":[["b",{"x":1}],["b",{"x":2}]],"c":3}');
COMMIT;
),
'002_pgbench_concurrent_transaction_savepoints' => q(
BEGIN;
SAVEPOINT s1;
INSERT INTO tbl VALUES(0, '[[14,2,3]]');
COMMIT;
),
'002_pgbench_concurrent_cic' => q(
SELECT pg_try_advisory_lock(42)::integer AS gotlock \gset
\if :gotlock
DROP INDEX CONCURRENTLY idx;
CREATE INDEX CONCURRENTLY idx ON tbl(i);
DROP INDEX CONCURRENTLY ginidx;
CREATE INDEX CONCURRENTLY ginidx ON tbl USING gin(j);
SELECT bt_index_check('idx',true);
SELECT gin_index_check('ginidx');
SELECT pg_advisory_unlock(42);
\endif
)
});
# Test bt_index_parent_check() with indexes created with
# CREATE INDEX CONCURRENTLY.
$node->safe_psql('postgres', q(CREATE TABLE quebec(i int primary key)));
# Insert two rows into index
$node->safe_psql('postgres',
q(INSERT INTO quebec SELECT i FROM generate_series(1, 2) s(i);));
# start background transaction
my $in_progress_h = $node->background_psql('postgres');
$in_progress_h->query_safe(q(BEGIN; SELECT pg_current_xact_id();));
# delete one row from table, while background transaction is in progress
$node->safe_psql('postgres', q(DELETE FROM quebec WHERE i = 1;));
# create index concurrently, which will skip the deleted row
$node->safe_psql('postgres',
q(CREATE INDEX CONCURRENTLY oscar ON quebec(i);));
# check index using bt_index_parent_check
my $result = $node->psql('postgres',
q(SELECT bt_index_parent_check('oscar', heapallindexed => true)));
is($result, '0', 'bt_index_parent_check for CIC after removed row');
$in_progress_h->quit;
$node->stop;
done_testing();