Re: PoC plpgsql - possibility to force custom or generic plan

2017-09-08 19:14 GMT+02:00 Simon Riggs <simon(at)2ndquadrant(dot)com>:

> On 6 September 2017 at 07:43, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>
> > LET custom_plan_tries = 0 IN SELECT ...
>
> Tom has pointed me at this proposal, since on another thread I asked
> for something very similar. (No need to reprise that discussion, but I
> wanted prepared queries to be able to do SET work_mem = X; SELECT).
> This idea looks a good way forward to me.
>
> Since we're all in roughly the same place, I'd like to propose that we
> proceed with the following syntax... whether or not this precisely
> solves OP's issue on this thread.
>
> 1. Allow SET to set multiple parameters...
> SET guc1 = x, guc2 = y
> This looks fairly straightforward
>
> 2. Allow a SET to apply only for a single statement
> SET guc1 = x, guc2 = y FOR stmt
> e.g. SET max_parallel_workers = 4 FOR SELECT count(*) FROM bigtable
> Internally a GUC setting already exists for a single use, via
> GUC_ACTION_SAVE, so we just need to invoke it.
>
> Quick prototype seems like it will deliver quite quickly. I couldn't
> see a reason to use "LET" rather than just "SET" which would be the
> POLA choice.
>
> Thoughts?
>

why not

Pavel

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> Simon Riggs http://www.2ndQuadrant.com/
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