On Sat, Nov 03, 2007 at 11:42:39AM +0400, rihad wrote: > Does this mean that a condition like "WHERE ... [AND] lhs.a=rhs.b [AND] > ..." where rhs.b is already unique-indexed, also requires (non-unique) > index on lhs.a for maximal join speed? Otherwise why would they want to > say that?
No, as long as one of the two columns is indexed it can help. An index on both might help if you need a lot of rows but it's a bit hard to construct a situation where it'd be obvious. Have a nice day, -- Martijn van Oosterhout <[EMAIL PROTECTED]> http://svana.org/kleptog/ > Those who make peaceful revolution impossible will make violent revolution > inevitable. > -- John F Kennedy
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