@RaviPrasad.Adiraju The properties which are optimized for reporting and the default OOTB properties that are important for reporting are available as independent separate columns in the work table. Rest of the properties whether its Single value, Page List, Page Group etc which are not exposed for reporting are present in the BLOB column in the XML format. Data with in the BLOB column for each work object is stored in XML format converted in binary format inside the BLOB column. So if you need to retrieve the data for any attribute that is not exposed in the table or not available as separate column in the table, data of the attribute can be retrieved by leveraging 

pr_read_from_stream('Property Name', pzInsKey, pzPVStream) function.

This is the only option to get the data from BLOB column.

Thanks

Chaitanya. 

@RaviPrasad.Adiraju ,

In Pega, when data is stored in the BLOB column (typically named pzPVStream in tables like pc_work), it's in a compressed and serialized format. You can't directly view the list of properties (columns) stored inside the BLOB using a standard SQL query, because they are not stored as individual database columns.

Regards,

Mohd Qizer Uddin