Specifying where condition in filter stage

[Bilwakunj]

Hi,
Can someone please let me know how to write the Where clause in the filter statement for following:
1. using wild card -- something similar like '%' in Oracle. For example my oracle where clause something like this:
where city='A%' -- how in the where clause of filter
2. where city IS NULL-- how to write such where clause in filter stage

I tried the way we write in ORACLE, but it didn't work.

[ray.wurlod]

In the Parallel Job Developer's Guide is specifically states (page 29-3) that the second argument with LIKE must be a regular expression (that is, a UNIX regular expression). It also states that IS NULL and IS NOT NULL are supported as operators.