Horton

Re: [POC] hash partitioning

Robert Haas <robertmhaas@gmail.com>

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From: Robert Haas <robertmhaas@gmail.com>
To: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
Cc: amul sul <sulamul@gmail.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: 2017-11-02T09:02:25Z
Lists: pgsql-hackers 
On Thu, Nov 2, 2017 at 1:52 PM, Ashutosh Bapat
<ashutosh.bapat@enterprisedb.com> wrote:
> Right now partition keys are immutable but we don't have much code
> written with that assumption. All the code usually keeps a lock on the
> parent till the time they use the information in the partition key. In
> a distant future, which may not exist, we may support ALTER TABLE ...
> PARTITION BY to change partition keys (albeit at huge cost of data
> movement). If we do that, we will have to remember this one-off
> instance of code which assumes that the partition keys are immutable.

I am pretty sure this is by no means the only piece of code which assumes that.

-- 
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.