Merlin Moncure wrote: > On 4/11/06, Simon Dale <sdale@xxxxxx> wrote: > > I'm trying to evaluate PostgreSQL as a database that will have to store a > > high volume of data and access that data frequently. One of the features on > > our wish list is to be able to use stored procedures to access the data and > > I was wondering if it is usual for stored procedures to perform slower on > > PostgreSQL than raw SQL? > > pl/pgsql procedures are a very thin layer over the query engine. > Generally, they run about the same speed as SQL but you are not making > apples to apples comparison. One of the few but annoying limitations > of pl/pgsql procedures is that you can't return a select directly from > the query engine but have to go through the return/return next > paradigm which will be slower than raw query for obvious reasons. There's one problem that hasn't been mentioned. For the optimizer a PL/pgSQL function (really, a function in any language except SQL) is a black box. If you have a complex join of two or three functions, and they don't return 1000 rows, it's very likely that the optimizer is going to get it wrong. -- Alvaro Herrera http://www.CommandPrompt.com/ The PostgreSQL Company - Command Prompt, Inc.
