Re: Performance question

In article <6d3o58$ntm$1@news.xmission.com>, Guillermo Labatte <labatteg@usa.net> writes > >Hi, >I have been told that > >select * from table1 where col between value1 and value2> >is faster than > >select * from table1 where col>=value1 and col<=value2> Proably little difference. I just prefer the first syntax as it is clearer what you mean.. >Is that true for Online 5.07? > >How about > >select * from table1 where col in (value1,value2,value3,value4, ...)> That will do a sequential scan of the table >vs > >select * from table1 where col=value1 or col=value2 or col=value3 or ...> and so will that instead do select * from table1 where col1=value1 union select * from table1 where col1=value2 union select * from table1 where col1=value3 union select * from table1 where col1=value4 Or course with PDQ enabled the way this can be parallelized is more obvious to the engine... Can anyone confirm that with PDQPRIORITY=1 i.e. parallel scans that unions are scanned in parallel? >? > >Thanks > -- David Williams Maintainer of the Informix FAQ Primary site (Beta Version) http://www.smooth1.demon.co.uk Official site http://www.iiug.org/techinfo/faq/faq_top.html I see you standin', Standin' on your own, It's such a lonely place for you, For you to be If you need a shoulder, Or if you need a friend, I'll be here standing, Until the bitter end... So don't chastise me Or think I, I mean you harm... All I ever wanted Was for you To know that I care