Horton

Re: [POC] hash partitioning

Robert Haas <robertmhaas@gmail.com>

View thread View on postgr.es
From: Robert Haas <robertmhaas@gmail.com>
To: amul sul <sulamul@gmail.com>
Cc: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>, Jesper Pedersen <jesper.pedersen@redhat.com>, Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>, Thom Brown <thom@linux.com>, Dilip Kumar <dilipbalaut@gmail.com>, Yugo Nagata <nagata@sraoss.co.jp>, David Steele <david@pgmasters.net>, Greg Stark <stark@mit.edu>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2017-10-12T14:05:26Z
Lists: pgsql-hackers 
On Thu, Oct 12, 2017 at 9:08 AM, amul sul <sulamul@gmail.com> wrote:
> How about combining high 32 bits and the low 32 bits separately as shown below?
>
> static inline uint64
> hash_combine64(uint64 a, uint64 b)
> {
>     return (((uint64) hash_combine((uint32) a >> 32, (uint32) b >> 32) << 32)
>             | hash_combine((unit32) a, (unit32) b));
> }

I doubt that's the best approach, but I don't have something specific
to recommend.

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

Commits

  1. Add hash partitioning.

  2. Add sanity check for pg_proc.provariadic

  3. Add hash_combine64.

  4. Make RelationGetPartitionDispatchInfo expand depth-first.

  5. Introduce 64-bit hash functions with a 64-bit seed.

  6. pg_dump: Add a --load-via-partition-root option.