Re: [POC] hash partitioning

Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>

From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
To: amul sul <sulamul@gmail.com>
Cc: Jesper Pedersen <jesper.pedersen@redhat.com>, Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>, Thom Brown <thom@linux.com>, Robert Haas <robertmhaas@gmail.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: 2017-10-16T09:06:01Z
Lists: pgsql-hackers
On Tue, Oct 10, 2017 at 4:37 PM, amul sul <sulamul@gmail.com> wrote:
> On Tue, Oct 10, 2017 at 3:42 PM, Ashutosh Bapat
> <ashutosh.bapat@enterprisedb.com> wrote:
>> On Tue, Oct 10, 2017 at 3:32 PM, amul sul <sulamul@gmail.com> wrote:
>>
>>>> +                                    hash_part? true : key->parttypbyval[j],
>>>> +                                    key->parttyplen[j]);
>>>> parttyplen is the length of partition key attribute, whereas what you want here
>>>> is the length of type of modulus and remainder. Is that correct? Probably we
>>>> need some special handling wherever parttyplen and parttypbyval is used e.g. in
>>>> call to partition_bounds_equal() from build_joinrel_partition_info().
>>>>
>>>
>>> Unless I am missing something, I don't think we should worry about parttyplen
>>> because in the datumCopy() when the datatype is pass-by-value then typelen
>>> is ignored.
>>
>> That's true, but it's ugly, passing typbyvalue of one type and len of other.
>>
>
> How about the attached patch(0003)?
> Also, the dim variable is renamed to natts.

Probably we should move changes to partition_bounds_copy() in 0003 to
0001, whose name suggests so.

-- 
Best Wishes,
Ashutosh Bapat
EnterpriseDB Corporation
The Postgres Database 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.