[rt-users] *very* slow 'OR' searches

[Michael Loftis]

--On Sunday, April 03, 2005 1:45 PM -0400 Dan Riley 
<dsr at mail.lns.cornell.edu> wrote:

> I find it somewhat worrisome that it is so easy to stumble across a
> simple search that takes essentially forever.  Presumably this happens
> because neither the query builder nor the MySQL "optimizer" notices

MySQL doesn't have an optimizer, at all.  Basically it takes a best guess 
based on query term ordering and available indices.  It's reliable and 
predictable but the programmer (or in this cas search builder) has to do 
all the real work.

> that the first term of the query doesn't depend on Attachments or
> Transactions, and so misses the opportunity to move the restrictions
> from the second term into JOIN clauses.  In general this is probably a
> hard problem to solve, but couldn't the query builder do better on the
> simple "apples OR oranges" search?