Re: Asynchronous Append on postgres_fdw nodes.

Andrei Lepikhov <a.lepikhov@postgrespro.ru>

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From: "Andrey V. Lepikhov" <a.lepikhov@postgrespro.ru>

To: Kyotaro Horiguchi <horikyota.ntt@gmail.com>

Cc: etsuro.fujita@gmail.com, movead.li@highgo.ca, pgsql-hackers@lists.postgresql.org

Date: 2020-06-15T03:51:23Z

Lists: pgsql-hackers

Attachments

frgn2n.sh (application/x-shellscript)
explain_partial_aggregates_problem.txt (text/plain)

The patch has a problem with partitionwise aggregates.

Asynchronous append do not allow the planner to use partial aggregates. 
Example you can see in attachment. I can't understand why: costs of 
partitionwise join are less.
Initial script and explains of the query with and without the patch you 
can see in attachment.

-- 
Andrey Lepikhov
Postgres Professional
https://postgrespro.com

Commits

Improve comments for trivial_subqueryscan().
- 4a8a5dd7f59c 15.0 landed
Disable asynchronous execution if using gating Result nodes.
- ebb790241523 14.3 landed
- 5c854e7a2c8a 15.0 landed
Allow asynchronous execution in more cases.
- c2bb02bc2e85 15.0 landed
Doc: Further update documentation for asynchronous execution.
- eab81953682d 14.0 landed
Fix rescanning of async-aware Append nodes.
- f3baaf28a6da 14.0 landed
Doc: Update documentation for asynchronous execution.
- 15fcd33e0694 14.0 landed
Fix EXPLAIN ANALYZE for async-capable nodes.
- a363bc6da96b 14.0 landed
Minor code cleanup in asynchronous execution support.
- bb684c82f733 14.0 landed
Adjust input value to WaitEventSetWait() in ExecAppendAsyncEventWait().
- a8af856d3257 14.0 landed
Add support for asynchronous execution.
- 27e1f14563cf 14.0 landed