On Wed, Aug 5, 2009 at 14:54, Bryan Pendleton<[email protected]> wrote:
> Great!
>
> Can you construct a UNION of the two queries, and then ORDER BY the UNION?
>
> And, in that case, does it use the index for both the union-ed subqueries?
This is the first time I've used UNION, but I tried this:
SELECT id, field, text, docfreq FROM Terms
WHERE field = ? AND text > ?
UNION ALL
SELECT id, field, text, docfreq FROM Terms
WHERE field > ?
ORDER BY field ASC, text ASC
And yes, it is still doing two separate index scans in this situation,
but code-wise it's far superior to doing each query separately as I
don't need to keep track of how many items I got from the first query.
The performance is basically identical.
Daniel
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Senior Developer The world's most advanced
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