On 20/10/2012 17:50, Tom Lane wrote: > "Raymond O'Donnell" <rod@xxxxxx> writes: >> On 20/10/2012 17:23, Tom Lane wrote: >>> FWIW, Postgres is reasonably smart about the case of multiple window >>> functions with identical window definitions --- once you've got one >>> lag() in the query, adding more isn't going to cost much. > >> Out of curiosity, would there be much difference between having multiple >> lag()s in the SELECT and a single one in a CTE? > > Not sure what you're proposing? I don't see how you'd solve this > problem with a CTE, at least not without a join, which seems unlikely > to be a win. Yes, I see what you mean.... was waving my hands a bit. :-) Ray. -- Raymond O'Donnell :: Galway :: Ireland rod@xxxxxx -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
