Horton

Re: Hash Indexes

Amit Kapila <amit.kapila16@gmail.com>

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From: Amit Kapila <amit.kapila16@gmail.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Jesper Pedersen <jesper.pedersen@redhat.com>, Jeff Janes <jeff.janes@gmail.com>, Mithun Cy <mithun.cy@enterprisedb.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2016-10-24T14:36:51Z
Lists: pgsql-hackers 
On Mon, Oct 24, 2016 at 8:00 PM, Amit Kapila <amit.kapila16@gmail.com> wrote:
> On Thu, Sep 29, 2016 at 6:04 AM, Robert Haas <robertmhaas@gmail.com> wrote:
>> On Wed, Sep 28, 2016 at 3:04 PM, Robert Haas <robertmhaas@gmail.com> wrote:
>
>
> Thanks for the valuable feedback.
>

Forgot to mention that in addition to fixing the review comments, I
had made an additional change to skip the dead tuple while copying
tuples from old bucket to new bucket during split.  This was
previously not possible because split and scan were blocking
operations (split used to take Exclusive lock on bucket and Scan used
to hold Share lock on bucket till the operation ends), but now it is
possible and during scan some of the tuples can be marked as dead.
Similarly during squeeze operation, skipping dead tuples while moving
tuples across buckets.

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

Commits

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

  2. Fix race introduced by 6d46f4783efe457f74816a75173eb23ed8930020.

  3. Improve hash index bucket split behavior.

  4. Reduce pinning and buffer content locking for btree scans.