Information for the Database Administrator

Locks and the Spool Files

CA-Datacom/DB supports record-level locking. It does not support a table lock or any type of member-level locking as in SAS. If a procedure requests member-level locking, the interface view engine creates an intermediate file of the SAS records, sometimes called a spool file. This spool file guarantees static data required by the SAS procedure, but at a potentially high processing cost.

A spool file is created if all the following conditions are true:

The file is opened with member-level locking.
The file is opened for sequential retrievals.
The file is opened for a procedure that requires multiple passes or "by-rewinds".

Note: The spool file creates a temporary file of static data. It does not prevent other users from changing the data in the table. [cautionend]

The processing costs might be so high that some tables cannot be processed. Therefore, a DDBLOCK= data set option is available that instructs the interface view engine not to build the intermediate file. If DDBLOCK equals 1, a warning message appears, but the procedure continues to execute. The user executes the procedure at his own risk. Presumably, that user is the only one using the table or the table is under exclusive use by some method separate from SAS.

Alternatively, if you are concerned about keeping the data static while the SAS procedure executes, you could extract the CA-Datacom/DB data into a SAS data file, then run the procedure against that data file.

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