Re: How to write efficient SQL Statement?

It all depends on the version of Informix, the indexes on the table and any 'ORDER BY' statement. The best way to find out how a particular statement is evaluated is to use 'SET EXPLAIN ON' so that you can see the Query Execution Plan. Since I don't know what kind of access you have to the backend machine it's hard for me to sugget how you might get to view it. In article <34edbd07.3196399@news.netvigator.com>, '''' Thenardier <Thenardier@POBoxes.com> writes > >Hi, > >I'm new to Informix. But now i'm ask to develop a system on >an Informix platform as backend and PowerBuilder 5.0 as frontend. >I wonder how Informix interpret SQL statements. Say in a SQL >statement like: > >SELECT id, name FROM tableA >WHERE criteriaA = 'XXX' AND > criteriaB = 'YYY' AND > criteriaC = 'CCC';> >What would Informix do to this? Reading criteriaC >first then go up, or from up to down? Can anyone tell? > >Btw, any good book u can suggest? > >Thanx!!!!! > > >Thenard -- Surfer! http://www.nevis-vieww.demon.co.uk Hopeful anti-spam: alter double 'w' to single 'w' to view site & send Email.