Improve FSM management for BRIN indexes. BRIN indexes like to propagate additions of free space into the upper pages of their free space maps as soon as the new space is known, even when it's just on one individual index page. Previously this required calling FreeSpaceMapVacuum, which is quite an expensive thing if the map is large. Use the FreeSpaceMapVacuumRange function recently added by commit c79f6df75 to reduce the amount of work done for this purpose.
Fix a couple of places that neglected to do the upper-page vacuuming at all after recording new free space. If the policy is to be that BRIN should do that, it should do it everywhere. Do RecordPageWithFreeSpace unconditionally in brin_page_cleanup, and do FreeSpaceMapVacuum unconditionally in brin_vacuum_scan. Because of the FSM's imprecise storage of free space, the old complications here seldom bought anything, they just slowed things down. This approach also provides a predictable path for FSM corruption to be repaired. Remove premature RecordPageWithFreeSpace call in brin_getinsertbuffer where it's about to return an extended page to the caller. The caller should do that, instead, after it's inserted its new tuple. Fix the one caller that forgot to do so. Simplify logic in brin_doupdate's same-page-update case by postponing brin_initialize_empty_new_buffer to after the critical section; I see little point in doing it before. Avoid repeat calls of RelationGetNumberOfBlocks in brin_vacuum_scan. Avoid duplicate BufferGetBlockNumber and BufferGetPage calls in a couple of places where we already had the right values. Move a BRIN_elog debug logging call out of a critical section; that's pretty unsafe and I don't think it buys us anything to not wait till after the critical section. Move the "*extended = false" step in brin_getinsertbuffer into the routine's main loop. There's no actual bug there, since the loop can't iterate with *extended still true, but it doesn't seem very future-proof as coded; and it's certainly not documented as a loop invariant. This is all from follow-on investigation inspired by commit c79f6df75. Discussion: https://postgr.es/m/5801.1522429...@sss.pgh.pa.us Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/1383e2a1a937116e1367c9584984f0730f9ef4d5 Modified Files -------------- src/backend/access/brin/brin.c | 29 +++--- src/backend/access/brin/brin_pageops.c | 155 ++++++++++++++++++--------------- src/include/access/brin_pageops.h | 2 +- 3 files changed, 103 insertions(+), 83 deletions(-)