On 25/11/14 22:24, David G Johnston wrote:
Thanks List, I think this is the right way to go.
Adrian Klaver-4 wrote
If I am only interested in get 2 entries per result set, I would expect
to see
Actually <=2.
How do you determine which rows to keep, by id or something else?
1 xx,yy
2 xx,yy
1,dd,zz
2,dd,zz
1, ee,ff
Using LIMIT only gives
1 xx,yy
2 xx,yy
Sorry for not explaining it very, I want to limit the size of an
inviduail set of records which is part of set of records.
It would help if we could see the actual query you are using to get the
result sets, suitably anonymized if needed.
The general answer is that you use a window clause and a row_number()
function over an appropriate partiton. Put that in a subquery then in the
outer query add a where clause for row_number <= 2.
David J.
--
View this message in context: http://postgresql.nabble.com/returning-only-part-of-a-rule-set-tp5828217p5828226.html
Sent from the PostgreSQL - general mailing list archive at Nabble.com.
--
Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general
