While querying the primavera tables, what column/field can be used to filter projects from baselines

When we query the database tables, what column/field can e used to filter out the baseline projects:

Example : 

Select Count(T.PROJ_ID), P.Name from Projectx P

Inner join Task T on P.Proj_ID=T.Proj_id

where T.Create_Date>=P.SumActualStartDate

and P.SumActualStartDate is not null

  group by P.Name

The above query lists the results for baseline projects as well.What project field is apt to be used to filter out baseline projects.