Horton

Re: [HACKERS] Partition-wise aggregation/grouping

Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>

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From: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>
To: Jeevan Chalke <jeevan.chalke@enterprisedb.com>
Cc: Robert Haas <robertmhaas@gmail.com>, Dilip Kumar <dilipbalaut@gmail.com>, David Rowley <david.rowley@2ndquadrant.com>, Rajkumar Raghuwanshi <rajkumar.raghuwanshi@enterprisedb.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2018-03-29T10:43:50Z
Lists: pgsql-hackers 
On Wed, Mar 28, 2018 at 7:21 PM, Ashutosh Bapat
<ashutosh.bapat@enterprisedb.com> wrote:
>
> Ah sorry, I was wrong about remote_conds. remote_conds and local_conds
> are basically the conditions on the relation being pushed down.
> havingQuals are conditions on a grouped relation so treating them like
> baserestrictinfo or join conditions looks more straight forward,
> rather than having a separate member in PgFdwRelationInfo. So, remote
> havingQuals go into remote_conds and local havingQuals go to
> local_conds.

Looks like we already do that. Then we have remote_conds, local_conds
which together should be equivalent to havingQual. Storing all those
three doesn't make sense. In future someone may use havingQual instead
of remote_conds/local_conds just because its available and then there
is risk of these three lists going out of sync.

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

Commits

  1. postgres_fdw: Push down partition-wise aggregation.

  2. Remove 'target' from GroupPathExtraData.

  3. Implement partition-wise grouping/aggregation.

  4. Don't pass the grouping target around unnecessarily.

  5. Determine grouping strategies in create_grouping_paths.

  6. Defer creation of partially-grouped relation until it's needed.

  7. Split create_grouping_paths into degenerate and non-degenerate cases.

  8. Pass additional arguments to a couple of grouping-related functions.

  9. Fix logic error in add_paths_to_partial_grouping_rel.

  10. Minor cleanup of code related to partially_grouped_rel.

  11. Add a new upper planner relation for partially-aggregated results.

  12. Charge cpu_tuple_cost * 0.5 for Append and MergeAppend nodes.

  13. Rename enable_partition_wise_join to enable_partitionwise_join

  14. Factor some code out of create_grouping_paths.

  15. Pad XLogReaderState's main_data buffer more aggressively.

  16. Prevent int128 from requiring more than MAXALIGN alignment.

  17. Fix DROP SUBSCRIPTION hang

  18. Inject $(ICU_LIBS) regardless of platform.

  19. Some preliminary refactoring towards partitionwise join.