EXISTS / IN - does it work on Postgresql?

On 19 Sep 2001 paula@cyberlazarus.net wrote:

Hello there,

Finally I got a \"yes\" and I\'m moving from Microsoft SQL Server to
Postgresql. I\'m using PHP4 and PHPLIB to work with query
abstractions. I have a lot of subqueries like:

WHERE ... EXISTS (SELECT ...)

I was researching and found ambiguous information about this kind of
subqueries, is that working fine with Postgresql?

In general, yes. Although IN (<subquery>) queries are rather slow right
now and you might want to look at rewriting those as EXISTS (...)
instead (there's an FAQ item on this with a very simple example).

paula@cyberlazarus.net writes:

WHERE ... EXISTS (SELECT ...)

I was researching and found ambiguous information about this kind of subqueries, is that working fine with Postgresql?

Yes.

--
Peter Eisentraut peter_e@gmx.net http://funkturm.homeip.net/~peter