Horton

Re: Problems with plan estimates in postgres_fdw

Etsuro Fujita <fujita.etsuro@lab.ntt.co.jp>

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From: Etsuro Fujita <fujita.etsuro@lab.ntt.co.jp>
To: Antonin Houska <ah@cybertec.at>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Andrew Gierth <andrew@tao11.riddles.org.uk>, pgsql-hackers@postgresql.org
Date: 2019-03-05T09:28:07Z
Lists: pgsql-hackers 
(2019/03/01 20:16), Antonin Houska wrote:
> Etsuro Fujita<fujita.etsuro@lab.ntt.co.jp>  wrote:

>> Conversely, it appears that add_foreign_ordered_paths() added by the patchset
>> would generate such pre-sorted paths *redundantly* when the input_rel is the
>> final scan/join relation.  Will look into that.
>
> Currently I have no idea how to check the plan created by FDW at the
> UPPERREL_ORDERED stage, except for removing the sort from the
> UPPERREL_GROUP_AGG stage as I proposed here:
>
> https://www.postgresql.org/message-id/11807.1549564431%40localhost

I don't understand your words "how to check the plan created by FDW". 
Could you elaborate on that a bit more?

Best regards,
Etsuro Fujita

Commits

  1. postgres_fdw: Perform the (FINAL, NULL) upperrel operations remotely.

  2. Refactor create_limit_path() to share cost adjustment code with FDWs.

  3. postgres_fdw: Modify regression tests for EPQ-related planning problems.

  4. postgres_fdw: Perform the (ORDERED, NULL) upperrel operations remotely.

  5. Save PathTargets for distinct/ordered relations in root->upper_targets[].

  6. Split create_foreignscan_path() into three functions.

  7. Fix test case for 'outer pathkeys do not match mergeclauses' fix.

  8. postgres_fdw: Avoid 'outer pathkeys do not match mergeclauses' error.