Re: proposal: schema variables

Pavel Stehule <pavel.stehule@gmail.com>

From: Pavel Stehule <pavel.stehule@gmail.com>

To: Erik Rijkers <er@xs4all.nl>

Cc: 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: 2021-04-10T06:58:41Z

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 →

Move WAL sequence code into its own file
- a87987cafca6 19 (unreleased) cited
Add ExplainState argument to pg_plan_query() and planner().
- c83ac02ec730 19 (unreleased) cited
Don't include access/htup_details.h in executor/tuptable.h
- 1a8b5b11e48a 19 (unreleased) cited
Refactor to avoid code duplication in transformPLAssignStmt.
- b0fb2c6aa5a4 19 (unreleased) cited
Avoid including commands/dbcommands.h in so many places
- 325fc0ab14d1 19 (unreleased) cited
Restrict psql meta-commands in plain-text dumps.
- 71ea0d679543 19 (unreleased) cited
Split func.sgml into more manageable pieces
- 4e23c9ef65ac 19 (unreleased) cited
Fix squashing algorithm for query texts
- 0f65f3eec478 18.0 cited
EXPLAIN: Always use two fractional digits for row counts.
- 95dbd827f2ed 18.0 cited
Preliminary refactoring of plpgsql expression construction.
- a654af21ae52 18.0 cited
plpgsql: pure parser and reentrant scanner
- 7b27f5fd36cb 18.0 cited
Add some sanity checks in executor for query ID reporting
- 24f520594809 18.0 cited
Fix misleading error message context
- 4af123ad45bd 18.0 cited
Add macros for looping through a List without a ListCell.
- 14dd0f27d7cd 17.0 cited

Attachments

schema-variables-rev2-20210410.patch.gz (application/gzip) patch

Hi

I am sending a strongly updated patch for schema variables.

I rewrote an execution of a LET statement. In the previous implementation I
hacked STMT_SELECT. Now, I introduced a new statement STMT_LET, and I
implemented a new executor node SetVariable. Now I think this
implementation is much cleaner. Implementation with own executor node
reduces necessary work on PL side - and allows the LET statement to be
prepared - what is important from a security view.

I'll try to write a second implementation based on a cleaner implementation
like utility command too. I expect so this version will be more simple, but
utility commands cannot be prepared, and probably, there should be special
support for any PL. I hope a cleaner implementation can help to move this
patch.

We can choose one variant in the next step and this variant can be
finalized.

Notes, comments?

Regards

Pavel