pgsql: Use streaming read for VACUUM cleanup of GIN

Started by Michael Paquier5 months ago1 messagescomitters

michael@paquier.xyz

5 months ago

Use streaming read for VACUUM cleanup of GIN

This commit replace the synchronous ReadBufferExtended() loop done in
ginvacuumcleanup() with the streaming read equivalent, to improve I/O
efficiency during GIN index vacuum cleanup operations.

With dm_delay to emulate some latency and debug_io_direct=data to force
synchronous writes and force the read path to be exercised, the author
has noticed a 5x improvement in runtime, with a substantial reduction in
IO stats numbers. I have reproduced similar numbers while running
similar tests, with improvements becoming better with more tuples and
more pages manipulated.

Author: Xuneng Zhou <xunengzhou@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Nazir Bilal Yavuz <byavuz81@gmail.com>
Discussion: /messages/by-id/CABPTF7VrqfbcDXqGrdLQ2xaQ=K0RzExNuw6U_GGqzSJu32wfdQ@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/6c228755add8f0714677440d53a160f9ed332902

Modified Files
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src/backend/access/gin/ginvacuum.c | 28 ++++++++++++++++++++++++++--
1 file changed, 26 insertions(+), 2 deletions(-)