pgsql: Add pg_buffercache_evict_{relation,all} functions - Mailing list pgsql-committers

From Andres Freund
Subject pgsql: Add pg_buffercache_evict_{relation,all} functions
Date
Msg-id E1u22ZM-003Fe0-0D@gemulon.postgresql.org
Whole thread Raw
List pgsql-committers
Add pg_buffercache_evict_{relation,all} functions

In addition to the added functions, the pg_buffercache_evict() function now
shows whether the buffer was flushed.

pg_buffercache_evict_relation(): Evicts all shared buffers in a
relation at once.
pg_buffercache_evict_all(): Evicts all shared buffers at once.

Both functions provide mechanism to evict multiple shared buffers at
once. They are designed to address the inefficiency of repeatedly calling
pg_buffercache_evict() for each individual buffer, which can be time-consuming
when dealing with large shared buffer pools. (e.g., ~477ms vs. ~2576ms for
16GB of fully populated shared buffers).

These functions are intended for developer testing and debugging
purposes and are available to superusers only.

Minimal tests for the new functions are included. Also, there was no test for
pg_buffercache_evict(), test for this added too.

No new extension version is needed, as it was already increased this release
by ba2a3c2302f.

Author: Nazir Bilal Yavuz <byavuz81@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Aidar Imamov <a.imamov@postgrespro.ru>
Reviewed-by: Joseph Koshakow <koshy44@gmail.com>
Discussion: https://postgr.es/m/CAN55FZ0h_YoSqqutxV6DES1RW8ig6wcA8CR9rJk358YRMxZFmw%40mail.gmail.com

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/dcf7e1697ba75ce7883ad7c6bc26ba24422eb892

Modified Files
--------------
contrib/pg_buffercache/expected/pg_buffercache.out |  64 ++++++++
.../pg_buffercache/pg_buffercache--1.5--1.6.sql    |  24 +++
contrib/pg_buffercache/pg_buffercache_pages.c      | 127 ++++++++++++++-
contrib/pg_buffercache/sql/pg_buffercache.sql      |  42 +++++
doc/src/sgml/pgbuffercache.sgml                    |  75 ++++++++-
src/backend/storage/buffer/bufmgr.c                | 175 ++++++++++++++++++---
src/include/storage/bufmgr.h                       |   9 +-
src/test/modules/test_aio/test_aio.c               |   6 +-
8 files changed, 483 insertions(+), 39 deletions(-)


pgsql-committers by date:

Previous
From: David Rowley
Date:
Subject: pgsql: Speedup child EquivalenceMember lookup in planner
Next
From: Andres Freund
Date:
Subject: pgsql: Increase BAS_BULKREAD based on effective_io_concurrency