Re: [HACKERS] Re: Subselects open issue Nr. NEW
Michael Hirohama <kamesan@ricochet.net>
From: Michael Hirohama <kamesan@ricochet.net>
To: "Vadim B. Mikheev" <vadim@sable.krasnoyarsk.su>
Cc: hackers@postgreSQL.org
Date: 1998-02-17T04:14:40Z
Lists: pgsql-hackers
At 10:31 +0700 2/17/98, Vadim B. Mikheev wrote: [...] > >I understand this. And this is how it works currently: > >select * from tab where (A,B) >= ANY (select X, Y from tab2); > >means: select tuples where A >= X _and_ B >= Y for some tuple from tab2. > ^^^^^ > 'AND' is used for all Op-s except for '<>' when 'OR' is used. > >Question is "should we drop this feature (?) or leave it as is ?" > >Comments ? > >Vadim I recommend dropping this feature and only supporing =ANY and <>ANY. Supporing the relational operators cannot be optimized in the general case. If I needed to perform the <=ANY query efficiently, I might use a functional index on 'A' and 'B' using an R-tree method. Regards, -- Michael Hirohama <kamesan@ricochet.net>