Horton

Re: proposal: schema variables

Josef Šimánek <josef.simanek@gmail.com>

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From: Josef Šimánek <josef.simanek@gmail.com>
To: Pavel Stehule <pavel.stehule@gmail.com>
Cc: Erik Rijkers <er@xs4all.nl>, Michael Paquier <michael@paquier.xyz>, Zhihong Yu <zyu@yugabyte.com>, Amit Kapila <amit.kapila16@gmail.com>, DUVAL REMI <REMI.DUVAL@cheops.fr>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2021-01-14T10:31:33Z
Lists: pgsql-hackers, pgsql-performance

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Move WAL sequence code into its own file

  2. Add ExplainState argument to pg_plan_query() and planner().

  3. Don't include access/htup_details.h in executor/tuptable.h

  4. Refactor to avoid code duplication in transformPLAssignStmt.

  5. Avoid including commands/dbcommands.h in so many places

  6. Restrict psql meta-commands in plain-text dumps.

  7. Split func.sgml into more manageable pieces

  8. Fix squashing algorithm for query texts

  9. EXPLAIN: Always use two fractional digits for row counts.

  10. Preliminary refactoring of plpgsql expression construction.

  11. plpgsql: pure parser and reentrant scanner

  12. Add some sanity checks in executor for query ID reporting

  13. Fix misleading error message context

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

I did some testing locally. All runs smoothly, compiled without warning.

Later on (once merged) it would be nice to write down a documentation
page for the whole feature as a set next to documented individual
commands.
It took me a few moments to understand how this works.

I was looking how to create variable with non default value in one
command, but if I understand it correctly, that's not the purpose.
Variable lives in a schema with default value, but you can set it per
session via LET.

Thus "CREATE VARIABLE" statement should not be usually part of
"classic" queries, but it should be threatened more like TABLE or
other DDL statements.

On the other side LET is there to use the variable in "classic" queries.

Does that make sense? Feel free to ping me if any help with
documentation would be needed. I can try to prepare an initial
variables guide once I'll ensure I do  understand this feature well.

PS: Now it is clear to me why it is called "schema variables", not
"session variables".

čt 14. 1. 2021 v 7:36 odesílatel Pavel Stehule <pavel.stehule@gmail.com> napsal:
>
> Hi
>
> rebase
>
> Regards
>
> Pavel
>