Well, the one index: CREATE INDEX acceptedbilling_to_date_accepted_billing_dt_idx ON acceptedbilling USING btree (to_date(accepted_billing_dt::text, 'yyyymmdd'::text));.
Reject: ERROR: functions in index expression must be marked IMMUTABLE SQL state: 42P17 Is actually a date stored in a varchar field (stupid I know, but it's a continual fight between the me (the dba), management, and our COBOL programmers). I was indexing it as a date so that I can treat it as a date in some of the non-COBOL programs/utilities that we have written. The second index is rather stupid, it was an early index before I figured out how to split a timestamp. Anyway, is there a way to make the first index work? Otherwise we end up with a seq scan on our billing table which is very painful. Thanks, Chris On 6/6/07, Tom Lane <[EMAIL PROTECTED]> wrote:
Alvaro Herrera <[EMAIL PROTECTED]> writes: > You can't do this because to_date and other functions are not immutable. > 8.2 seems to be more picky about this -- the date conversions of > timestamptz columns are dependent on the current timezone. The reason 8.2 is more picky is that the function is less immutable thanks to the addition of locale-dependent functionality: http://archives.postgresql.org/pgsql-committers/2006-11/msg00264.php I gather that the underlying column is timestamp without tz, or it would never have worked in 8.1 either. That being the case, these index definitions seem pretty darn stupid anyway --- why aren't you just indexing on date_trunc or a plain cast to date? regards, tom lane
