Re: Union Query Improvement
От | Ron Johnson |
---|---|
Тема | Re: Union Query Improvement |
Дата | |
Msg-id | 45D2BA53.2010100@cox.net обсуждение исходный текст |
Ответ на | Union Query Improvement (Ray Bannon <bannonr@comcast.net>) |
Список | pgsql-general |
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 02/13/07 07:46, Ray Bannon wrote: > I have a query which is running a bit slowly, and I'm wondering if anyone > has a design improvement. Basically it's a series of unions as follows: > > Select ID, plan_name from table/view > Where plan_name = 'A' > And rownum = 1 > UNION > Select ID, plan_name from table/view > Where plan_name = 'B' > And rownum = 1 > UNION > Select ID, plan_name from table/view > Where plan_name = 'C' > And rownum = 1 > UNION > > Ad infinitum for about 100 iterations. > > Any way to write this more efficiently? Just out of curiosity: why does your(?) design have 100 tables/views with the same (or almost identical) structure? -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) iD8DBQFF0rpTS9HxQb37XmcRAtH5AJ4zz5NPM5rBsNWLrKC+/Md6GhxCNgCfZBHf AeMbTRNKp4guK81pGwfU5wc= =t9y+ -----END PGP SIGNATURE-----
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