Re: Checkpoint cost, looks like it is WAL/CRC - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Checkpoint cost, looks like it is WAL/CRC
Date
Msg-id 3153.1120709425@sss.pgh.pa.us
Whole thread Raw
In response to Re: Checkpoint cost, looks like it is WAL/CRC  (Bruce Momjian <pgman@candle.pha.pa.us>)
Responses Re: Checkpoint cost, looks like it is WAL/CRC  (Bruce Momjian <pgman@candle.pha.pa.us>)
List pgsql-hackers
Bruce Momjian <pgman@candle.pha.pa.us> writes:
> As far as #2, my posted proposal was to write the full pages to WAL when
> they are written to the file system, and not when they are first
> modified in the shared buffers ---

That is *completely* unworkable.  Or were you planning to abandon the
promise that a transaction is committed when we have flushed its WAL
commit record?

> Seems it is similar to fsync in risk, which is not a new option.

The point here is that fsync-off is only realistic for development
or playpen installations.  You don't turn it off in a production
machine, and I can't see that you'd turn off the full-page-write
option either.  So we have not solved anyone's performance problem.
        regards, tom lane


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