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Re: Rethinking plpgsql's assignment implementation

Pavel Stehule <pavel.stehule@gmail.com>

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From: Pavel Stehule <pavel.stehule@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Chapman Flack <chap@anastigmatix.net>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2020-12-27T23:08:59Z
Lists: pgsql-hackers 
so 26. 12. 2020 v 19:00 odesílatel Pavel Stehule <pavel.stehule@gmail.com>
napsal:

> Hi
>
> I repeated tests. I wrote a set of simple functions. It is a synthetical
> test, but I think it can identify potential problems well.
>
> I calculated the average of 3 cycles and I checked the performance of each
> function. I didn't find any problem. The total execution time is well too.
> Patched code is about 11% faster than master (14sec x 15.8sec). So there is
> new important functionality with nice performance benefits.
>
> make check-world passed
>

I played with plpgsql_check tests and again I didn't find any significant
issue of this patch. I am very satisfied with implementation.

Now, the behavior of  SELECT INTO is behind the assign statement and this
fact should be documented. Usually we don't need to use array's fields
here, but somebody can try it.

Regards

Pavel



> Regards
>
> Pavel
>
>
>
>

Commits

  1. Rethink the "read/write parameter" mechanism in pl/pgsql.

  2. Remove PLPGSQL_DTYPE_ARRAYELEM datum type within pl/pgsql.

  3. Re-implement pl/pgsql's expression and assignment parsing.

  4. Add the ability for the core grammar to have more than one parse target.

  5. Support subscripting of arbitrary types, not only arrays.

  6. Improve handling of array elements as getdiag_targets and cursor_variables.