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 <[email protected]>
Reviewed-by: Michael Paquier <[email protected]>
Reviewed-by: Nazir Bilal Yavuz <[email protected]>
Discussion: 
https://postgr.es/m/CABPTF7VrqfbcDXqGrdLQ2xaQ=k0rzexnuw6u_ggqzsju32w...@mail.gmail.com

Branch
------
master

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

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

Reply via email to