Horton

Re: Parallel bitmap heap scan

Dilip Kumar <dilipbalaut@gmail.com>

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From: Dilip Kumar <dilipbalaut@gmail.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Andres Freund <andres@anarazel.de>, 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: 2017-02-08T13:58:28Z
Lists: pgsql-hackers

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On Wed, Feb 8, 2017 at 7:01 PM, Robert Haas <robertmhaas@gmail.com> wrote:
> You can store whatever you want in SH_TYPE's private_data member.
> SH_ALLOCATE and SH_FREE both get a pointer to the SH_TYPE, so they
> have access to that.  Hmm, but there's no way to get that set in
> SH_CREATE before SH_ALLOCATE is called.  Maybe we need to add a
> private_data argument to SH_CREATE.  execGrouping.c could use that
> instead of frobbing private_data directly:
>
> -    hashtable->hashtab = tuplehash_create(tablecxt, nbuckets);
> -    hashtable->hashtab->private_data = hashtable;
> +    hashtable->hashtab = tuplehash_create(tablecxt, nbuckets, hashtable);

Okay, will go ahead as you suggested. Patch attached for the same.


-- 
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com

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.