Hey Craig, Things like pre-parsed prepared statements that're re-planned on every > execution are often proposed as solutions to this. This has me wondering: > rather than expensively re-planning from scratch, would it be possiblet to > adjust the planning process so that *multiple* alternative plans would be > cached for a query, using placeholders for unknown rowcounts and costs? At > execution, the unknown costs would be filled in and the plans compared then > the best plan picked for this execution. Is this crazy talk, or could it > significantly reduce the cost of re-planning parameterized prepared > statements to the point where it'd be worth doing by default? > Its a good suggestion of some kind of optimization at the server side. This idea can be extended to an "auto-prepare" mode (like an auto-commit mode that we have today in Postgres). But its not so hard to let the application (or library) to decide what to use in different cases: prepared statement or regular statement. Thus, I think it is not worth it...
-- > Craig Ringer > > -- > Sent via pgsql-general mailing list (pgsql-general@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/**mailpref/pgsql-general<http://www.postgresql.org/mailpref/pgsql-general> > -- // Dmitriy.
