[7.3.3] select with stable function not being optimized to index scan

Your name : Barrie Slaymaker
Your email address : barries(at)slaysys(dot)com

System Configuration
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Architecture (example: Intel Pentium) : Pentium

Operating System (example: Linux 2.0.26 ELF) : WinXP+cygwin

PostgreSQL version (example: PostgreSQL-7.3.3): PostgreSQL-7.3.3

Compiler used (example: gcc 2.95.2) :

Please enter a FULL description of your problem:
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Stable functions aren't elevated to index scans.

Please describe a way to repeat the problem. Please try to provide a
concise reproducible example, if at all possible:
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interchange=# create or replace function int8foo() returns int8 as
'BEGIN RETURN 1; END' language 'plpgsql' stable; CREATE FUNCTION mydb=#
explain select * from ann where fax_key = int8foo();
QUERY PLAN
---------------------------------------------------------
Seq Scan on ann (cost=0.00..2524.55 rows=8 width=1012)
Filter: (fax_key = int8foo())
(2 rows)

mydb=# explain select * from ann where fax_key = 1;
QUERY PLAN
--------------------------------------------------------------------------------
Index Scan using ann_fax_key_index on ann (cost=0.00..3.11 rows=7
width=1012)
Index Cond: (fax_key = 1)
(2 rows)

mydb=# create or replace function int8foo() returns int8 as 'select
1::int8' language 'sql' stable; CREATE FUNCTION mydb=# explain select *
from ann where fax_key = int8foo();
QUERY PLAN
---------------------------------------------------------
Seq Scan on ann (cost=0.00..2524.55 rows=8 width=1012)
Filter: (fax_key = int8foo())
(2 rows)
mydb=#

If you know how this problem might be fixed, list the solution below:
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If you know how this problem might be fixed, list the solution below:
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