On 7/13/07, Malcolm Tredinnick <[EMAIL PROTECTED]> wrote: [...] > Due to Oracle inclusion, this has to be > > select count(*) from [table] where [...] > > and then check that the result is > 0, at least in the Oracle backend > (no "limit" extension in Oracle). The problem being that count(*) is not > an optimised operation in PostgreSQL, however, we haven't yet split up > those cases in a lot of the code (the recent Oracle merge moved a bunch > of similar things to the count(*) case and I keep meaning to look at > whether we can move them all to count(id_col), which is faster).
Just curious: In which backends is count(id_col) faster than count(*)?. I'd say that any decent database engine should take both as the same (as long as a PK exists and no outer joins are performed), but I could be wrong and would be happy to know why. -- Leo Soto M. --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Django developers" group. To post to this group, send email to django-developers@googlegroups.com To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/django-developers?hl=en -~----------~----~----~----~------~----~------~--~---
