Horton

Re: Hash Indexes

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: Jeff Janes <jeff.janes@gmail.com>, Jesper Pedersen <jesper.pedersen@redhat.com>, Mithun Cy <mithun.cy@enterprisedb.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2016-09-15T14:13:29Z
Lists: pgsql-hackers 
On Thu, Sep 15, 2016 at 1:41 AM, Amit Kapila <amit.kapila16@gmail.com> wrote:
> I think it is possible without breaking pg_upgrade, if we match all
> items of a page at once (and save them as local copy), rather than
> matching item-by-item as we do now.  We are already doing similar for
> btree, refer explanation of BTScanPosItem and BTScanPosData in
> nbtree.h.

If ever we want to sort hash buckets by TID, it would be best to do
that in v10 since we're presumably going to be recommending a REINDEX
anyway.  But is that a good thing to do?  That's a little harder to
say.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

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.