Horton

Re: Eager aggregation, take 3

Richard Guo <guofenglinux@gmail.com>

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From: Richard Guo <guofenglinux@gmail.com>
To: jian he <jian.universality@gmail.com>
Cc: Robert Haas <robertmhaas@gmail.com>, Tender Wang <tndrwang@gmail.com>, Paul George <p.a.george19@gmail.com>, Andy Fan <zhihuifan1213@163.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>, pgsql-hackers@lists.postgresql.org
Date: 2024-10-29T07:56:56Z
Lists: pgsql-hackers 
On Fri, Oct 18, 2024 at 10:22 PM jian he <jian.universality@gmail.com> wrote:
> So overall I doubt here BTEQUALIMAGE_PROC flag usage is correct.

The BTEQUALIMAGE_PROC flag is used to prevent eager aggregation for
types whose equality operators do not imply bitwise equality, such as
NUMERIC.

After a second thought, I think it should be OK to just check the
equality operator specified by the SortGroupClause for btree equality.
I’m not very sure about this point, though, and would appreciate any
inputs.

Thanks
Richard

Commits

  1. Fix eager aggregation for semi/antijoin inner rels

  2. Cover additional errors and corner conditions in repack.c

  3. Fix volatile function evaluation in eager aggregation

  4. Fix collation handling for grouping keys in eager aggregation

  5. Rename apply_at to apply_agg_at for clarity

  6. Fix comment in eager_aggregate.sql

  7. Remove unnecessary include of "utils/fmgroids.h"

  8. Implement Eager Aggregation

  9. Allow negative aggtransspace to indicate unbounded state size

  10. Add macros for looping through a List without a ListCell.

  11. Account for the effect of lossy pages when costing bitmap scans.

  12. Fix a thinko in join_is_legal: when we decide we can implement a semijoin