postgresql/contrib/test_decoding/specs/catalog_change_snapshot.spec
Amit Kapila b793a416bf Fix catalog lookup due to wrong snapshot for subtransactions during decoding.
In commit 272248a0c, we fixed the catalog lookup due to the wrong snapshot
for transactions and subtransactions during decoding. We failed to
consider the case where top-level xact is already marked as containing
catalog change but its subtransaction is not yet marked as containing
catalog change even though it contained such a change.

This can happen when during decoding, none of the WAL records from the
subtransaction was decoded and top-level xact contains a DDL.

We fix it by marking the transaction and all its subtransactions as
containing catalog changes if the top-level xact contains any catalog
change and it is present in the initial running xacts array.

This fix is required only for 14 and 15 because in prior branches we
already always mark the transaction and all its subtransactions as
containing catalog changes in the same case. In 16 and above, we preserve
the list of transaction IDs and sub-transaction IDs, that have modified
catalogs and are running during snapshot serialization, to the serialized
snapshot (see commit 7f13ac8123).

Author: Fei Changhong
Reviewed-by: Amit Kapila, Hayato Kuroda, Andy Fan
Discussion: https://postgr.es/m/18280-4c8060178cb41750@postgresql.org
2024-01-29 10:42:41 +05:30

78 lines
4.5 KiB
Ruby

# Test decoding only the commit record of the transaction that have
# modified catalogs.
setup
{
DROP TABLE IF EXISTS tbl1;
DROP TABLE IF EXISTS tbl1_part;
CREATE TABLE tbl1 (val1 integer, val2 integer);
CREATE TABLE tbl1_part (val1 integer) PARTITION BY RANGE (val1);
CREATE TABLE user_cat (val1 integer) WITH (user_catalog_table = true);
}
teardown
{
DROP TABLE tbl1;
DROP TABLE tbl1_part;
DROP TABLE user_cat;
SELECT 'stop' FROM pg_drop_replication_slot('isolation_slot');
}
session "s0"
setup { SET synchronous_commit=on; }
step "s0_init" { SELECT 'init' FROM pg_create_logical_replication_slot('isolation_slot', 'test_decoding'); }
step "s0_begin" { BEGIN; }
step "s0_savepoint" { SAVEPOINT sp1; }
step "s0_savepoint_release" { RELEASE SAVEPOINT sp1; }
step "s0_truncate" { TRUNCATE tbl1; }
step "s0_insert" { INSERT INTO tbl1 VALUES (1); }
step "s0_insert2" { INSERT INTO user_cat VALUES (1); }
step "s0_insert_part" { INSERT INTO tbl1_part VALUES (1); }
step "s0_create_part1" { CREATE TABLE tbl1_part_p1 PARTITION OF tbl1_part FOR VALUES FROM (0) TO (10); }
step "s0_create_part2" { CREATE TABLE tbl1_part_p2 PARTITION OF tbl1_part FOR VALUES FROM (10) TO (20); }
step "s0_commit" { COMMIT; }
session "s1"
setup { SET synchronous_commit=on; }
step "s1_checkpoint" { CHECKPOINT; }
step "s1_get_changes" { SELECT data FROM pg_logical_slot_get_changes('isolation_slot', NULL, NULL, 'skip-empty-xacts', '1', 'include-xids', '0'); }
# For the transaction that TRUNCATEd the table tbl1, the last decoding decodes
# only its COMMIT record, because it starts from the RUNNING_XACTS record emitted
# during the first checkpoint execution. This transaction must be marked as
# containing catalog changes while decoding the COMMIT record and the decoding
# of the INSERT record must read the pg_class with the correct historic snapshot.
#
# Note that in a case where bgwriter wrote the RUNNING_XACTS record between "s0_commit"
# and "s0_begin", this doesn't happen as the decoding starts from the RUNNING_XACTS
# record written by bgwriter. One might think we can either stop the bgwriter or
# increase LOG_SNAPSHOT_INTERVAL_MS but it's not practical via tests.
permutation "s0_init" "s0_begin" "s0_savepoint" "s0_truncate" "s1_checkpoint" "s1_get_changes" "s0_commit" "s0_begin" "s0_insert" "s1_checkpoint" "s1_get_changes" "s0_commit" "s1_get_changes"
# Test that we can handle the case where there is no association between top-level
# transaction and its subtransactions. The last decoding restarts from the first
# checkpoint, decodes NEW_CID generated by "s0_insert2", and marks the subtransaction
# as containing catalog changes while adding tuple cids to its top-level transaction.
# During that, both transaction entries are created in ReorderBuffer as top-level
# transactions and have the same LSN. We check if the assertion check for the order
# of transaction LSNs in AssertTXNLsnOrder() is skipped since we are still before the
# LSN at which we start replaying the contents of transactions. Besides, when decoding
# the commit record of the top-level transaction, we must force the top-level
# transaction to do timetravel since one of its subtransactions has been marked as
# containing catalog changes.
permutation "s0_init" "s0_begin" "s0_savepoint" "s0_insert" "s1_checkpoint" "s1_get_changes" "s0_insert2" "s0_commit" "s0_begin" "s0_insert" "s1_checkpoint" "s1_get_changes" "s0_commit" "s1_get_changes"
# The last decoding restarts from the first checkpoint and adds invalidation
# messages generated by "s0_truncate" to the subtransaction. While
# processing the commit record for the top-level transaction, we decide
# to skip this xact but ensure that corresponding invalidation messages
# get processed.
permutation "s0_init" "s0_begin" "s0_savepoint" "s0_insert" "s1_checkpoint" "s1_get_changes" "s0_truncate" "s0_commit" "s0_begin" "s0_insert" "s1_checkpoint" "s1_get_changes" "s0_commit" "s1_get_changes"
# The last decoding restarts from the first checkpoint and doesn't decode
# any WAL records generated by the subtransaction that performed s0_create_part1.
# While processing the commit record for the corresponding top-level transaction
# which will be marked as containing catalog change even before commit, we ensure
# that the corresponding substransaction is also marked as containing a catalog
# modifying change.
permutation "s0_init" "s0_begin" "s0_savepoint" "s0_create_part1" "s0_savepoint_release" "s1_checkpoint" "s0_create_part2" "s0_commit" "s0_begin" "s0_truncate" "s1_checkpoint" "s1_get_changes" "s0_insert_part" "s1_get_changes" "s0_commit" "s1_get_changes"