AW: AW: vacuum - Mailing list pgsql-hackers

From Zeugswetter Andreas SB
Subject AW: AW: vacuum
Date
Msg-id 11C1E6749A55D411A9670001FA687963368324@sdexcsrv1.f000.d0188.sd.spardat.at
Whole thread Raw
List pgsql-hackers
> The other question is, what are your startup parameters? What sort of
> shared memory buffer are you working with?  I image that VACUUM does a
> flush to disk, so are 1000 items filling your buffer(s), 
> causing an almost
> continue fsync to disk for each INSERT after that ... so the VACUUM is
> clearing the buffer(s) to disk, giving your space again to do quick
> INSERTs for 1000 records again?

Aah yes, you mean that the pages are only written during checkpoints ?
Then he would not need a vacuum, but a forced checkpoint.
That would actually impose, that we need yet another checkpoint initiating
event, e.g. do checkpoint when buffer is 75% dirty. Or better yet have
a daemon, that only writes out dirty pages from back to front of the LRU queue
until only a configurable amount of buffers is dirty.

Andreas


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