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 [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/django-developers?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
