Horton

Re: Write Ahead Logging for Hash Indexes

Amit Kapila <amit.kapila16@gmail.com>

View thread View on postgr.es
From: Amit Kapila <amit.kapila16@gmail.com>
To: Jeff Janes <jeff.janes@gmail.com>
Cc: Jesper Pedersen <jesper.pedersen@redhat.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2016-09-25T05:00:33Z
Lists: pgsql-hackers

Attachments

On Fri, Sep 23, 2016 at 5:34 PM, Amit Kapila <amit.kapila16@gmail.com> wrote:
>
> I think here I am slightly wrong.  For the full page writes, it do use
> RBM_ZERO_AND_LOCK mode to read the page and for such mode we are not
> doing page verification check and rather blindly setting the page to
> zero and then overwrites it with full page image.  So after my fix,
> you will not see the error of checksum failure.  I have a fix ready,
> but still doing some more verification.  If everything passes, I will
> share the patch in a day or so.
>

Attached patch fixes the problem, now we do perform full page writes
for bitmap pages.  Apart from that, I have rebased the patch based on
latest concurrent index patch [1].  I have updated the README as well
to reflect the WAL logging related information for different
operations.

With attached patch, all the review comments or issues found till now
are addressed.


[1] - https://www.postgresql.org/message-id/CAA4eK1%2BX%3D8sUd1UCZDZnE3D9CGi9kw%2Bkjxp2Tnw7SX5w8pLBNw%40mail.gmail.com

-- 
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com

Commits

  1. Add a regression test for snapshot too old with hash indexes.

  2. hash: Add write-ahead logging support.

  3. Improve coding in _hash_addovflpage.

  4. Remove _hash_wrtbuf() in favor of calling MarkBufferDirty().

  5. Improve hash index bucket split behavior.