On Fri, 19 Nov 2004, Arshavir Grigorian wrote: > Hi, > > I have a query that when run on similar tables in 2 different databases > either uses the index on the column (primary key) in the where clause or > does a full table scan. The structure of the tables is the same, except > that the table where the index does not get used has an extra million > rows (22mil vs 23mil). > > The 2 boxes where these database run are very different (Sparc with scsi > disks and 2G RAM running Solaris 8 AND a PC with 128M RAM running and an > IDE drive running Linux RH9 2.4.20-20.9). I am not sure why that would > make a difference, but maybe it does. Is the second server running in "C" locale or a different locale? The optimization for LIKE to use indexes involves either making an index with a *_pattern_ops operator class or being in "C" locale.