On 2013-03-25 03:40, Anssi Kääriäinen wrote: > I am very likely going to change the ORM to use EXISTS subqueries > instead of IN subqueries. I know this is a good idea on PostgreSQL > but I don't have enough experience of other databases to know if > this is a good idea or not.
I can only speak for testing IN-vs-EXISTS speed on MSSQLServer at $OLD_JOB, but there it's usually about the same, occasionally with IN winning out. However, the wins were marginal, and MSSQL is a 2nd-class citizen in the Django world, so I'm +1 on using EXISTS instead of IN, if the results are assured to be the same. However, the query constuction to move the condition into the EXISTS subclause might be a bit more complex. -tkc -- You received this message because you are subscribed to the Google Groups "Django developers" group. To unsubscribe from this group and stop receiving emails from it, send an email to django-developers+unsubscr...@googlegroups.com. To post to this group, send email to django-developers@googlegroups.com. Visit this group at http://groups.google.com/group/django-developers?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
