[anarazel]

The largest part of the time executing the above query isn't inside the function, so this isn't that a material comparison. The reason for that is that SRFs in FROM to be materialized into a tuplestore, which isn't free:

    postgres[607045][1]=# SELECT count(*) FROM generate_series(1, 10000000);
    ┌──────────┐
    │  count   │
    ├──────────┤
    │ 10000000 │
    └──────────┘
    (1 row)

    Time: 1249.224 ms (00:01.249)

    postgres[607045][1]=# SELECT count(*) FROM (SELECT generate_series(1, 10000000)) s;
    ┌──────────┐
    │  count   │
    ├──────────┤
    │ 10000000 │
    └──────────┘
    (1 row)

    Time: 460.206 ms

For mostly historical reasons SRFs in the target list can use the non-materializing SRF query protocol, but SRFs in the FROM list can't.

Any chance you could show the timings for the pgx version of the second query?

[zombodb]

Sure! Top is Postgres, bottom is pgx, after running each 5 times...

    test=# SELECT count(*) FROM (SELECT generate_series(1, 10000000)) s;
      count   
    ----------
     10000000
    (1 row)

    Time: 399.630 ms
    test=# SELECT count(*) FROM (SELECT srf.generate_series(1, 10000000)) s;
      count   
    ----------
     10000000
    (1 row)

    Time: 478.194 ms

Thanks for the reply. I'm not surprised there's room for optimization in pgx, especially in the Iterator-->SRF path.

edit: PS, thanks for the idea of putting what I assume is the backend pid in psql's prompt. I need to go figure out how to do that right now!

edit edit: hmm, I guess that's not the PID.

[anarazel]

Thanks for the update.

> edit: PS, thanks for the idea of putting what I assume is the backend pid in psql's prompt. I need to go figure out how to do that right now!

Here's my ~/.psqlrc:

    andres@awork3:~/src/postgresql$ cat ~/.psqlrc
    \set QUIET 1

    \pset pager always
    \set VERBOSITY verbose
    \pset null '(null)'
    \set COMP_KEYWORD_CASE upper
    \pset linestyle unicode
    \pset border 2
    \set PROMPT1 '%/[%p][%l]%x%R%# '
    \set PROMPT2 '%/[%p][%l]%x%R%# '
    \set PROMPT3 'c:%/[%p][%l]%x%R%# '
    \set HISTCONTROL ignoredups
    \set HISTSIZE 100000

    \timing on
    \set QUIET 0