Gilles <[EMAIL PROTECTED]> wrote: > At 15:40 31/01/2008 -0800, James Dennett wrote: > > > WHERE col LIKE '123%' or WHERE substr(col,1, 3) = '123' > > > >The optimizer has a decent chance of using an index for LIKE '123%' but > >I'd be surprised (and impressed) if it looks inside function calls suchas > >substr for opportunities to use indexes. > > Thanks guys. I'll remember to index the column, for higher performance. >
Indices won't help with LIKE unless the column as a NOCASE collation. Use GLOB instead: ... WHERE number GLOB '1234*'; Note that "*" is the wildcard character with GLOB, not "%" as in LIKE. The above will use an index on the number column if it is available. -- D. Richard Hipp <[EMAIL PROTECTED]> ----------------------------------------------------------------------------- To unsubscribe, send email to [EMAIL PROTECTED] -----------------------------------------------------------------------------
