Horton

Re: Parallel bitmap heap scan

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Andres Freund <andres@anarazel.de>
Cc: Dilip Kumar <dilipbalaut@gmail.com>, Haribabu Kommi <kommi.haribabu@gmail.com>, Rafia Sabih <rafia.sabih@enterprisedb.com>, tushar <tushar.ahuja@enterprisedb.com>, Amit Khandekar <amitdkhan.pg@gmail.com>, Amit Kapila <amit.kapila16@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2017-02-07T22:14:19Z
Lists: pgsql-hackers 
On Tue, Feb 7, 2017 at 4:45 PM, Andres Freund <andres@anarazel.de> wrote:
> On 2017-02-07 16:36:55 -0500, Robert Haas wrote:
>> On Tue, Feb 7, 2017 at 4:15 PM, Andres Freund <andres@anarazel.de> wrote:
>> > FWIW, I think it'd have been better to not add the new callbacks as
>> > parameters to *_create(), but rather have them be "templatized" like the
>> > rest of simplehash.  That'd require that callback to check the context,
>> > to know whether it should use shared memory or not, but that seems fine
>> > to me.  Right now this pushes the head of simplehash above a
>> > cacheline...
>>
>> Something like the attached?
>
> Yes.
>
>> +#ifndef SH_USE_NONDEFAULT_ALLOCATOR
>> +
>
> That should probably be documented in the file header.

Right.  OK, did that and a few other cleanups, and committed.

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

Commits

  1. Pass DSA_ALLOC_HUGE when allocating a shared TIDBitmap.

  2. Support parallel bitmap heap scans.

  3. tidbitmap: Support shared iteration.

  4. Shut down Gather's children before shutting down Gather itself.

  5. Revise the way the element allocator for a simplehash is specified.

  6. Refactor bitmap heap scan estimation of heap pages fetched.

  7. Use more efficient hashtable for tidbitmap.c to speed up bitmap scans.