Horton

Re: PG 15 (and to a smaller degree 14) regression due to ExprEvalStep size

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Andrew Dunstan <andrew@dunslane.net>
Cc: Michael Paquier <michael@paquier.xyz>, Tom Lane <tgl@sss.pgh.pa.us>, David Rowley <dgrowleyml@gmail.com>, Peter Geoghegan <pg@bowt.ie>, PostgreSQL-development <pgsql-hackers@postgresql.org>, Nikita Glukhov <n.gluhov@postgrespro.ru>
Date: 2022-07-11T00:29:30Z
Lists: pgsql-hackers 
Hi,

On 2022-07-08 17:05:49 -0400, Andrew Dunstan wrote:
> Actually, it's not the same name: JsonCoercionsState vs
> JsonCoercionState. But I agree that it's a subtle enough difference that
> we should use something more obvious. Maybe JsonCoercionStates instead
> of JsonCoercionsState? The plural at the end would be harder to miss.

Given that it's a one-off use struct, why name it? Then we don't have to
figure out a name we never use.

I also still would like to understand why we need pre-allocated space for all
these types. How could multiple datums be coerced in an interleaved manner?
And if that's possible, why can't multiple datums of the same type be coerced
at the same time?

Greetings,

Andres Freund

Commits

  1. JSON_TABLE: Add support for NESTED paths and columns

  2. Add basic JSON_TABLE() functionality

  3. Add SQL/JSON query functions

  4. Add soft error handling to some expression nodes

  5. Adjust populate_record_field() to handle errors softly

  6. Refactor code used by jsonpath executor to fetch variables

  7. Add more SQL/JSON constructor functions

  8. SQL/JSON: support the IS JSON predicate

  9. SQL/JSON: add standard JSON constructor functions

  10. Add static assertion ensuring sizeof(ExprEvalStep) <= 64 bytes

  11. Remove size increase in ExprEvalStep caused by hashed saops

  12. pgstat: reduce timer overhead by leaving timer running.

  13. expression eval: Fix EEOP_JSON_CONSTRUCTOR and EEOP_JSONEXPR size.

  14. SQL/JSON query functions

  15. Speedup ScalarArrayOpExpr evaluation