| From: | Alvaro Herrera <alvherre(at)2ndquadrant(dot)com> |
|---|---|
| To: | Fabien COELHO <coelho(at)cri(dot)ensmp(dot)fr> |
| Cc: | Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>, Tatsuo Ishii <ishii(at)sraoss(dot)co(dot)jp>, rafia(dot)sabih(at)enterprisedb(dot)com, Michael Paquier <michael(dot)paquier(at)gmail(dot)com>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Amit Langote <Langote_Amit_f8(at)lab(dot)ntt(dot)co(dot)jp>, Robert Haas <robertmhaas(at)gmail(dot)com>, PostgreSQL Developers <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: [HACKERS] pgbench - allow to store select results into variables |
| Date: | 2018-11-16 21:43:07 |
| Message-ID: | 20181116214307.uhpir3nvwuvjftxa@alvherre.pgsql |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On 2017-Nov-04, Fabien COELHO wrote:
> Think of one initialization followed by two appends:
>
> SELECT 1 AS x \cset
> SELECT 2 \; SELECT 3 AS y \cset
> SELECT 4 \; SELECT 5 \; SELECT 6 AS z \gset
>
> In the end, we must have the full 6 queries
>
> "SELECT 1 AS x \; SELECT 2 \; SELECT 3 AS y \; SELECT 4 \; SELECT 5 \; SELECT 6 AS z"
>
> and know that we want to set variables from queries 1, 3 and 6 and ignore
> the 3 others.
I'm not sure I understand this. Why is the "SELECT 2" ignored? (I can
see why the 4 and 5 are ignored: they are not processed by gset).
What exactly does \cset do? I thought "SELECT 2 \; SELECT 3 AS y \cset"
would search for the \; and process *both* queries.
I think the doc addition should be split.
--
Álvaro Herrera https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Thomas Munro | 2018-11-16 21:53:20 | Re: Refactoring the checkpointer's fsync request queue |
| Previous Message | Tom Lane | 2018-11-16 21:15:10 | Re: Early WIP/PoC for inlining CTEs |