Re: planner used functional index in 7.3.6, now does a seq scan in 7.4.7 after upgrade

Chris Tennant <postgresql-ctennant@elirious.com> writes:
> here's the definition of the function (as immutable):

> CREATE OR REPLACE FUNCTION stereo_id (INTEGER, INTEGER, INTEGER) RETURNS 
> INTEGER AS
>      'BEGIN  RETURN CASE WHEN $2 = $3 THEN $1 ELSE -1 END;    END;'
>    LANGUAGE 'plpgsql' IMMUTABLE;

> and here's the original definition of the functional index:

> CREATE INDEX stereo_pair_image_attributes_stereo_id
>     ON opt_stereo_pair_image_attributes
>         (stereo_id(right_patient_data_id,left_patient_data_id));

Um, that index seems to be on some other function that may have the same
name, but only takes two arguments?
        regards, tom lane