If you select the FMS Group Attributes option in File System Groups File Maintenance for a file system group with FMS type 8, the FMS Controls overlay for DB2 appears as shown in Figure 2-22-A below.
Figure 2-22-A. FMS Controls Overlay for DB2 (Type 8)
The DB2 overlay contains these fields:
· Data Source Name defines the particular DB2 source being used.
· Table Naming Scheme assists APPX in translating its 8-character file names to the DB2 external table names. If users will be accessing the DB2 source at the File System Group level, then a “Table Naming Scheme” is entered here. Select the Hints option for help on constructing a table-naming scheme. See the Table Naming Scheme Hints section for an example of the Hints overlay. If you intend to override these parameters at the file level in Database Management, then you can leave this field blank and enter an explicit table name there.
· Proxy Database ID identifies the Proxy Database; a proxy database is used for row-level locking. Choose a value that you have not used for a real database.
· Suppress Null Numerics? determines whether or not to disable the null numeric feature inherent in the database; answer "yes" 
if you want to be consistent with APPXIO behavior which does not have this capability (a zero entry cannot be distinguished from a null value in APPXIO).
· Read Uncommitted? determines whether or not to read a record with an update pending which has not yet been committed; "no" 
is recommended in order to emulate APPXIO behavior.