Hi Martin, I have the following list of tables in database schema: sql>\d TABLE sys.customer TABLE sys.lineitem TABLE sys.nation TABLE sys.orders TABLE sys.part TABLE sys.partsupp TABLE sys.region TABLE sys.supplier Please can you point me to the C code file(s) that hold the BAT objects for each column of the above tables please? I want to debug and analyse specifically that part of the code region that declares, initialises and maintains the list of BAT structures for the tables. The following query is providing the information about the tables and I am assuming that this query also access this information from all the individual BAT structures of a database schema. select * from storage() where "table" = 'lineitem'; Secondly, Is it possible to list of get the list of all the BAT structures (Column BATS and Delta BATs) in the running database please? Thanks. Kind Regards, Ahmad