Horton

Re: Declarative partitioning - another take

Jaime Casanova <jaime.casanova@2ndquadrant.com>

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From: Jaime Casanova <jaime.casanova@2ndquadrant.com>
To: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>
Cc: Robert Haas <robertmhaas@gmail.com>, Amit Langote <amitlangote09@gmail.com>, Rajkumar Raghuwanshi <rajkumar.raghuwanshi@enterprisedb.com>, Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2016-11-07T17:15:24Z
Lists: pgsql-hackers

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On 28 October 2016 at 02:53, Amit Langote <Langote_Amit_f8@lab.ntt.co.jp> wrote:
>
> Please find attached the latest version of the patches

Hi,

I started to review the functionality of this patch, so i applied all
9 patches. After that i found this warning, which i guess is because
it needs a cast.

After that, i tried a case that i think is important: to partition an
already existing table. Because there is no ALTER TABL SET PARTITION
or something similar (which i think makes sense because such a command
would need to create the partitions and move the rows to follow the
rule that there is no rows in a parent table).

So, what i tried was:

1) rename original table
2) create a new partitioned table with old name
3) attach old table as a partition with bounds outside normal bounds
and no validate

the idea is to start attaching valid partitions and delete and insert
rows from the invalid one (is there a better way of doing that?), that
will allow to partition a table easily.
So far so good, until i decided points 1 to 3 should happen inside a
transaction to make things transparent to the user.

Attached is script that shows the failure when trying it:

script 1 (failing_test_1.sql) fails the assert
"Assert(RelationGetPartitionKey(parentRel) != NULL);" in
transformAttachPartition() at src/backend/parser/parse_utilcmd.c:3164

After that i tried the same but with an already partitioned (via
inheritance) table and got this (i did this first without a
transaction, doing it with a transaction will show the same failure as
before):

script 2 (failing_test_2.sql) fails the assert
"Assert(childrte->relkind == RELKIND_PARTITIONED_TABLE);" in
expand_inherited_rte_internal() at
src/backend/optimizer/prep/prepunion.c:1551

PS: i don't like the START END syntax but i don't have any ideas
there... except, there was a reason not to use expressions (like a
CHECK constraint?)

-- 
Jaime Casanova                      www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Commits

  1. Fix typo.

  2. Document trigger-firing behavior for inheritance/partitioning.

  3. Fire per-statement triggers on partitioned tables.

  4. Set ecxt_scantuple correctly for tuple routing.

  5. Fix interaction of partitioned tables with BulkInsertState.

  6. Avoid core dump for empty prepared statement in an aborted transaction.

  7. Fix some problems in check_new_partition_bound().

  8. Remove unnecessary arguments from partitioning functions.

  9. Fix reporting of constraint violations for table partitioning.

  10. Fix tuple routing in cases where tuple descriptors don't match.

  11. Invalid parent's relcache after CREATE TABLE .. PARTITION OF.

  12. Doc: improve documentation about inheritance.