The underlying problem turned out to be using an function returning=20
int8 on a column of type int. When the function is altered to return=20
int, an index scan is used.
On Dec 10 2003, Barrie Slaymaker wrote:
> Your name : Barrie Slaymaker
> Your email address : barries@slaysys.com
>=20
>=20
> System Configuration
> ---------------------
> Architecture (example: Intel Pentium) : Pentium
>=20
> Operating System (example: Linux 2.0.26 ELF) : WinXP+cygwin
>=20
> PostgreSQL version (example: PostgreSQL-7.3.3): PostgreSQL-7.3.3
>=20
> Compiler used (example: gcc 2.95.2) :
>=20
>=20
> Please enter a FULL description of your problem:
> ------------------------------------------------
>=20
> Stable functions aren't elevated to index scans.
>=20
>=20
>=20
> Please describe a way to repeat the problem. Please try to provide a
> concise reproducible example, if at all possible:=20
> ----------------------------------------------------------------------
>=20
>=20
>=20
> interchange=3D# create or replace function int8foo() returns int8 as=20
> 'BEGIN RETURN 1; END' language 'plpgsql' stable; CREATE FUNCTION=20
> mydb=3D# explain select * from ann where fax_key =3D int8foo();
> QUERY PLAN
> ---------------------------------------------------------
> Seq Scan on ann (cost=3D0.00..2524.55 rows=3D8 width=3D1012)
> Filter: (fax_key =3D int8foo())
> (2 rows)
>=20
> mydb=3D# explain select * from ann where fax_key =3D 1;
> QUERY PLAN=20
> -------------------------------------------------------------------------=
-------
> Index Scan using ann_fax_key_index on ann (cost=3D0.00..3.11 rows=3D7=20
> width=3D1012)
> Index Cond: (fax_key =3D 1)
> (2 rows)
>=20
> mydb=3D# create or replace function int8foo() returns int8 as 'select=20
> 1::int8' language 'sql' stable; CREATE FUNCTION mydb=3D# explain select=
=20
> * from ann where fax_key =3D int8foo();
> QUERY PLAN
> ---------------------------------------------------------
> Seq Scan on ann (cost=3D0.00..2524.55 rows=3D8 width=3D1012)
> Filter: (fax_key =3D int8foo())
> (2 rows)
> mydb=3D#
>=20
>=20
>=20
> If you know how this problem might be fixed, list the solution below:
> ---------------------------------------------------------------------
>=20
>=20
>=20
>=20
> If you know how this problem might be fixed, list the solution below:
> ---------------------------------------------------------------------
>=20
>=20
>=20
>
