Forcing Function recompilation in SQL 2000

A stored procedure in the cache is automatically recompiled when a table it refers to has a table structure change. User defined functions are not. Here's a simplified code sample:

set nocount on
go

create table tmpTest (a int, b int, c int)

insert into tmpTest (a, b, c) values (1, 2, 3)
insert into tmpTest (a, b, c) values (2, 3, 4)
go

if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[fTest]') and xtype in (N'FN', N'IF', N'TF'))
drop function [dbo].[fTest]
GO

CREATE FUNCTION dbo.fTest (@.a int)
RETURNS TABLE
AS
RETURN (SELECT * from tmpTest where a = @.a)
GO

select * from fTest(1)

CREATE TABLE dbo.Tmp_tmpTest
(
a int NULL,
b int NULL,
d int NULL,
c int NULL
) ON [PRIMARY]
IF EXISTS(SELECT * FROM dbo.tmpTest)
EXEC('INSERT INTO dbo.Tmp_tmpTest (a, b, c)
SELECT a, b, c FROM dbo.tmpTest TABLOCKX')
DROP TABLE dbo.tmpTest
EXECUTE sp_rename N'dbo.Tmp_tmpTest', N'tmpTest', 'OBJECT'

select * from fTest(1)

drop table tmpTest

Running it, the output is:

a b c
-- -- --
1 2 3

Caution: Changing any part of an object name could break scripts and stored procedures.
The OBJECT was renamed to 'tmpTest'.
a b c
-- -- --
1 2 NULL

(I know that "select *" is bad, but it's a lot of legacy code that I'm working with here, and that's how it's written.)

The function doesn't detect that the table has changed in structure, or even that there is no longer a dependency on tmpTest. (Appending a column rather than inserting has the same effect, in that only the first 3 columns are returned.)

DBCC FREEPROCCACHE has no effect, not that I really expected it to, but you never know...

Is there any way, other than dropping and recreating, to force a recompilation of a particular function in memory, or perhaps all functions?

Thanks in anticipation.

Tom

try this example from the Books Online...

USE pubs IF EXISTS (SELECT name FROM sysobjects WHERE name = 'titles_by_author' AND type = 'P') DROP PROCEDURE titles_by_author GO CREATE PROCEDURE titles_by_author @.@.LNAME_PATTERN varchar(30) = '%' WITH RECOMPILE AS SELECT RTRIM(au_fname) + ' ' + RTRIM(au_lname) AS 'Authors full name', title AS Title FROM authors a INNER JOIN titleauthor ta ON a.au_id = ta.au_id INNER JOIN titles t ON ta.title_id = t.title_id WHERE au_lname LIKE @.@.LNAME_PATTERN GO |||

Thanks for the suggestion. Just one small point:

It's a function, not a procedure. And WITH RECOMPILE isn't a valid option for a function.

Tom

|||It is because of the SELECT *. Inline table-valued function is similar to view in that the metadata for the columns are persisted at the time of creation of the function. So in your example, the * in the select list will get resolved to table/columns at creation time. You will have to run ALTER FUNCTION or drop/recreate the function to recreate the correct metadata in current versions of SQL Server. SQL Server 2005 SP2 will have a new system stored procedure that can be used to refresh such metadata for SPs, UDFs. This will be similar to sp_refreshview SP. Of course, you wouldn't get into these problems if you specified column names explicitly.