Hello,

How does the ROW compression (Db2 LUW Ver 9 and above ) treats the NULL Values in columns? If there are 10-12 column with NULL values, will row compression consider this for compression?
We can use value compression, but I guess we cannot use both value and row compression together?

Thanks,
Rajesh

They can be used together.

Andy

My understanding was that only nonnull fields are stored in a record on storage. After a few mb of these records(in 9.5) are inserted, in a table set for compression, a compression dictionary is built and subsequent records use tokens from the dictionary(if applicable). So null values do not enter the picture.