"Carlo Stonebanks" <stonec.register@xxxxxxxxxxxx> writes: > There is an index on lower(last_name). I have seen the planner convert the > LIKE to lower(last_name) >= 'smith' and lower(last_name) < 'smiti' on 8.2.4 > systems, but a slow sequence scan and filter on 8.1.9 - is this related to > the version difference (8.1.9 vs 8.2.4) or is this related to something like > operators/classes that have been installed? Most likely you used C locale for the 8.2.4 installation and some other locale for the other one. In non-C locale you can still get the optimization if you create an index using the text_pattern_ops opclass ... but beware that this index is useless for the normal locale-aware operators. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org