posted 18 years ago
You could try something like this:
With the folowing preconditions.
- index on et.phone_number, at.phone_number, at.banned
- 'SELECT et.column1, et.column2, ... ' should have the minimum number of column required by application
PS. as a general rule EXISTS has a better performance than IN in most of the cases
[ March 03, 2006: Message edited by: Balazs Borbely ]
'Make everything as simple as possible, but not simpler.' --Albert Einstein