Horton

Re: Write Ahead Logging for Hash Indexes

Mark Kirkwood <mark.kirkwood@catalyst.net.nz>

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From: Mark Kirkwood <mark.kirkwood@catalyst.net.nz>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: Jeff Janes <jeff.janes@gmail.com>, Ashutosh Sharma <ashu.coek88@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2016-09-11T07:16:04Z
Lists: pgsql-hackers 

On 11/09/16 17:01, Amit Kapila wrote:
> On Sun, Sep 11, 2016 at 4:10 AM, Mark Kirkwood
> <mark.kirkwood@catalyst.net.nz> wrote:
>>
>> performed several 10 hour runs on size 100 database using 32 and 64 clients.
>> For the last run I rebuilt with assertions enabled. No hangs or assertion
>> failures.
>>
> Thanks for verification.  Do you think we can do some read-only
> workload benchmarking using this server?  If yes, then probably you
> can use concurrent hash index patch [1] and cache the metapage patch
> [2] (I think Mithun needs to rebase his patch) to do so.
>
>
>
> [1] - https://www.postgresql.org/message-id/CAA4eK1J6b8O4PcEPqRxNYbLVbfToNMJEEm+qn0jZX31-obXrJw@mail.gmail.com
> [2] - https://www.postgresql.org/message-id/CAD__OuhJ29CeBif_fLGe4t9Vj_-cFXBwCXhjO+D_16TXbemY+g@mail.gmail.com
>
>

I can do - are we checking checking for hangs/assertions or comparing 
patched vs unpatched performance (for the metapage patch)?

regards

Mark

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.