"Mitch Vincent" <mitch@venux.net> writes:
> Using PostgreSQL 7.0 I'm Doing ...
> ipa2=# CREATE INDEX "app_stat_month" on applicant_stats(date(month));
> ERROR: SQL-language function not supported in this context.
> ipa2=# \d applicant_stats
> Table "applicant_stats"
> Attribute | Type | Modifier
> -----------+-----------+----------
> app_id | integer |
> month | date |
> user_id | integer |
> view_time | timestamp |
> Index: app_id
Since month is already a 'date', applying date() to it is pretty pointless.
I don't really know why we have date(date) defined at all, but we do,
and it's defined as an SQL-language function --- which indexes don't
support at the moment. Thus the error message.
There are a fair number of no-op functions in pg_proc that are defined
as SQL "SELECT $1". We could probably afford to lose 'em all, and let
the parser treat these things as implicit type conversions instead...
regards, tom lane
