A.51. Release 4.0.23

Use schema qualification for internal queries. (Tatsuo Ishii)

Some of objects such as function and cast did not use "pg_catalog." schema qualification. This does not lead to immediate security concern but using the schema qualification is always good practice.

Fix compile error on systems using musl libc. (bug 790) (Tatsuo Ishii)

Patch provided by leimaohui.

Fix multiple query cache bug. (Tatsuo Ishii)

Discussion: https://www.pgpool.net/pipermail/pgpool-hackers/2023-January/004259.html

Fix sr worker to not send wrong query to standby server in corner case. (Tatsuo Ishii)

When ALWAYS_PRIMARY flag is set, PRIMARY_NODE_ID macro returns node id, rather than -1 even if the primary is down. In this case streaming replication delay check worker sends SELECT pg_current_wal_lsn() or SELECT pg_current_xlog_location() depending on PostgreSQL's version to standby which of course raises an error.

Discussion: https://www.pgpool.net/pipermail/pgpool-hackers/2023-February/004279.html

Fix kind mismatch error with DEALLOCATE. (bug 780) (Tatsuo Ishii)

Kind mismatch error occurs when conditions below are all met:

• streaming replication mode

• load balance node is other than primary

• PREPARE is used in a multi-statement query

Add explanation for wd_priority. (Chen Ningwei)

Add restriction regarding PREPARE/EXECUTE/DEALLOCATE. (Tatsuo Ishii)

Add caution to use -D option with pgpool. (Tatsuo Ishii)

Enhancing "Installation from RPM" section. (Bo Peng)

Remove the configuration of "-D" start OPTS from "8.2. Pgpool-II + Watchdog Setup Example". (Bo Peng)

Mention that AES256 support requires --with-openssl option. (Tatsuo Ishii)

Explicitly stat that it is -w option of pcp command is needed to use .pcppass. (Tatsuo Ishii)

Enhance SHOW POOL_CACHE. (Tatsuo Ishii)

Refactor 071.execute_and_deallocate/test.sh. (Tatsuo Ishii)

Enhance regression tests. (Tatsuo Ishii)

Fix occasional 005.jdbc test failure. (Tatsuo Ishii)