On Tue, 2006-02-21 at 10:34, Alvaro Herrera wrote: > Scott Marlowe wrote: > > On Tue, 2006-02-21 at 09:57, Ibrahim Tekin wrote: > > > hi, > > > i have btree index on a text type field. i want see rows which starts > > > with certain characters on that field. so i write a query like this: > > > > > > SELECT * FROM mytable WHERE myfield LIKE 'john%' > > > > > > since this condition is from start of the field, query planner should > > > use index to find such elements but explain command shows me it will > > > do a sequential scan. > > > > > > is this lack of a feature or i am wrong somewhere? > > > > This is an artifact of how PostgreSQL handles locales other than ASCII. > > > > If you want such a query to use an index, you need to back up your > > database, and re-initdb with --locale=C as an argument. > > ... or you can choose to create an index with the text_pattern_ops > operator class, which would be used in a LIKE constraint regardless of > locale. > > http://www.postgresql.org/docs/8.1/static/indexes-opclass.html Good point. I tend to view the world from the perspective of the 7.4 and before user...
