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Hi, I have a question on implementation
of the LIMIT SQL clause. Using the LIMIT clause, I want
to reduce the computation time for a query. When I try to limit the result
of a joined table, however, the join will be computed first (which takes very long). Lets suppose the following example: select * from T1 join T2 on T1.id = T2.id LIMIT 1 Conceptually, it should be possible
to fetch one row from T1 and T2, i.e. to propagate the LIMIT clause. I was wondering what the
exact requirements are to propagate the LIMIT clause. Do I need a foreign key
relation between T1 and T2? Do I need to use a full outer
join in order to propagate the LIMIT clause? Thanks LUCAS Product Development Torex Retail Solutions GmbH Schwedenstr. 9,
D-13359 Berlin Tel. +49 (0) 30
49901-243 Fax +49 (0) 30
49901-139 |
- [HACKERS] LIMIT and JOINS Gregor Zeitlinger
- Re: [HACKERS] LIMIT and JOINS Tom Lane
