Passing a list as a parameter to a function

Question

Hi,
I am relatively new to PL/SQL, but am used to passing lists to functions in other languages. In my PL/SQL function, currently I assign a SELECT to a cursor, and in the WHERE clause for the select, I have something hardcoded like
WHERE field_name = ('apple', 'bat', 'cat').
I would like to replace it by something like
WHERE field_name = list_name
where list_name is passed as a parameter to the function that I am defining. The reason I want to do this is because my list_name can have many more than three things in the future.
Does PL/SQL support an easy way to do this? I have asked around with no success, but it seems to me that a language like PL/SQL ought to have something to support it, since just about every modern language does.
Thanks,
Regards,
Srini

Answer 1

The trickiest part of the asktom solution is ensuring the cardinality hint is used to help the optimizer understand that the in-list you are building likely contains only a handful of values instead of it 1 whole block worth assumption.
The default assumption without the cardnility hint will ensure that an index on the column that is used for the IN clause will never be used, resulting in horrible performance.
I think 10g fixes this, and does some dynamic sampling of the collections returned through that approach. I am not quite 100% sure about that, but I think that is the case.