How do I return my records grouped by NULL and NOT NULL?

Question

I have a table that has a processed_timestamp column -- if a record has been processed then that field contains the datetime it was processed, otherwise it is null.

Answer 1

Stewart,

Maybe consider this solution. It is (also!) vendor non-specific.

SELECT count([processed_timestamp]) AS notnullrows, 
       count(*) - count([processed_timestamp]) AS nullrows 
FROM table

As for efficiency, this avoids 2x index seeks/table scans/whatever by including the results on one row. If you absolutely require 2 rows in the result, two passes over the set may be unavoidable because of unioning aggregates.

Hope this helps