Re: v7.2.3 versus v7.3 -> huge performance penalty for JOIN with UNION

> Probably not, since the first thing it does is to flatten the
> sub-select, leaving it with a concatenation expression in the
> WHERE-clause.

Ah, I see.

So, I'll just split this thingy into two seperate queries, starting with
creating a temp table containing the straight subselect results.

> We really need to fix the planner to be able to do merge/hash on
> "arbitrary expression = arbitrary expression", not only "Var = Var".

I can get around it, so I'm not complaining ;-)


Tom, thanks a *lot* for the prompt responses !!



Best,





Frank.