Re: cannot index functions with multiple arguments

IIRC, index functions can take multiple arguments, it's just that
they cannot take constants.  I think the values must all be columns
of the tables. So for example, this should work (seems to at
least create on 7.1beta3):
create table aaa (a int, b int, c text);
create index blah on aaa(substr(c,a,b));

On Wed, 31 Jan 2001 pgsql-bugs@postgresql.org wrote:

> Scott Marlowe (smarlowe@ihs.com) reports a bug with a severity of 2
> The lower the number the more severe it is.
> 
> Short Description
> cannot index functions with multiple arguments
> 
> Long Description
> Postgresql version: 7.1beta2
> OS: RedHat Linux 7.0
> 
> Postgresql allows indexing of functions applied to columns, like so:
> 
> create index yada on table (lower(column));
> 
> but this fails on functions like substr that have multiple arguments.
> 
> create index yada on table (substr(column,1,4));
> 
> fails like so:
> 
> ERROR:  parser: parse error at or near "1"
> 
> Sample Code
> Exact code as I typed it in, with response:
> 
> smarlowe=# create index exten_extension_idx on exten  (substr(extension,1,4));
> ERROR:  parser: parse error at or near "1"
> 
> I hope this isn't a known bug and I'm reporting it again.
> 
> No file was uploaded with this report
>