Alban Hertroys <haramrae@xxxxxxxxx> writes: > On 10 May 2012 15:05, RadosÅ?aw Smogura <rsmogura@xxxxxxxxxxxxxxx> wrote: >> May I ask what kind of planning may occur during insert? > Well, for example, if there's a unique constraint on the table then > the database will have to check that the newly inserted values don't > conflict with values that are already in the table. It needs to plan > an efficient strategy for that, which depends on the values being > inserted. There is no planning associated with checking unique constraints; that's just a matter for the index mechanisms. I think the real point here is that a simple INSERT/VALUES has such a trivial plan that there is hardly any gain to be had by avoiding the planning stage. Then the other overhead of a prepared statement (looking up the saved plan, checking it's not stale, etc) outweighs that. Or at least it could. 3x slower seems a bit fishy; I wonder whether there's some client-side inefficiency involved in that. Doing performance measurements with pgAdmin seems pretty questionable in the first place ... regards, tom lane -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
