On Tue, 2012-11-27 at 09:56 -0500, Robert Blayzor wrote: > Does caching not work if you use the SQL in a macro?
It might - it depends. Have a look at the docs, Chap 9, section 8. The short way to look at this is that a lookup might be cached within an SMTP connection if, and only if, you can do a single lookup early enough to guarantee grabbing all the data you need. As an example, when running a valid address through "exim -bt" here at work I see a single MySQL lookup on the domain part which is subsequently re-used from the cache 4 additional times; but I also see two subsequent lookups which are based on data from the first which are not cached. For performance reasons you need to work out whether having a complex SQL query (with potential joins, and so on) is faster at returning all the data you want as compared to multiple, smaller lookups on indexed or optimised tables. There is no "right answer" to that, you can only figure that one out by instrumenting your system to see what it's doing. Graeme -- ## List details at https://lists.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/
