On 7 September 2017 at 11:31, Tom Lane <t...@sss.pgh.pa.us> wrote: > Simon Riggs <si...@2ndquadrant.com> writes: >> I would like to relax the restriction to allow this specific use case... >> SET work_mem = X; SET max_parallel_workers = 4; SELECT ... >> so we still have only one command (the last select), yet we have >> multiple GUC settings beforehand. > > On what basis do you claim that's only one command? It would return > multiple CommandCompletes, for starters, so that it breaks the protocol > just as effectively as any other loosening. > > Moreover, I imagine the semantics you really want is that the SETs only > apply for the duration of the command. This wouldn't provide that > result either.
> Haas' idea of some kind of syntactic extension, like "LET guc1 = x, > guc2 = y FOR statement" seems more feasible to me. I'm not necessarily > wedded to that particular syntax, but I think it has to look like > a single-statement construct of some kind. Always happy to use a good idea... (any better way to re-locate that discussion?) 1. Allow SET to set multiple parameters... SET guc1 = x, guc2 = y This looks fairly straightforward 2. Allow SET to work only for a single command... SET guc1 = x, guc2 = y FOR query Don't see anything too bad about that... Requires a new GUC mode for "statement local" rather than "transaction local" -- Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers