Re: Write Ahead Logging for Hash Indexes

On Mon, Dec 5, 2016 at 2:46 AM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>> I'll review after that, since I have other things to review meanwhile.
>
> Attached, please find the rebased patch attached with this e-mail.
> There is no fundamental change in patch except for adapting the new
> locking strategy in squeeze operation. I have done the sanity testing
> of the patch with master-standby setup and Kuntal has helped me to
> verify it with his wal-consistency checker patch.

This patch again needs a rebase, but before you do that I'd like to
make it harder by applying the attached patch to remove
_hash_chgbufaccess(), which I think is a bad plan for more or less the
same reasons that motivated the removal of _hash_wrtbuf() in commit
25216c98938495fd741bf585dcbef45b3a9ffd40. I think there's probably
more simplification and cleanup that can be done afterward in the wake
of this; what I've done here is just a mechanical replacement of
_hash_chgbufaccess() with LockBuffer() and/or MarkBufferDirty(). The
point is that having MarkBufferDirty() calls happen implicitly instead
some other function is not what we want for write-ahead logging. Your
patch gets rid of that, too; this is just doing it somewhat more
thoroughly.

--
Robert Haas
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