Tracking the State of Data Sets

The DATASETS client control table tracks the state of data sets. State information consists of the ds_mode value and the DMSII audit file location from which subsequent updates should be processed. The audit file location includes the AFN, the ABSN, the segment and index in the audit files, and the audit file time stamp. These values, which are collectively referred to as the stateinfo, are stored in the audit_filenum, audit_block, audit_seg, audit_inx, and audit_time6 of the DATASETS client control table. The column audit_ts contains a date/time value, which corresponds to the audit_time6 data, which is binary and represents a DMSII TIME(6) value. This last column is not part of the stateinfo; it's there because knowing the audit time stamp value can sometimes be very useful.

Each subsequent time you run a process command, the DATABridge Client passes the stateinfo and the mode of each data set to the DATABridge Engine. The Engine uses this information to determine whether data sets should be cloned and the starting location in the audit trail. From that starting location, the Engine begins processing updates to the DMSII database. Every time a transaction group ends, the DATABridge client updates the stateinfo for the data sets in the DATASETS client control table. At the end of the process command, the location of the last quiet point in the audit trail is saved in the DATASETS client control table. This is the starting point for the next Client run (process command).

If the in_sync column of a data set has a value of 1, its stateinfo columns may be out-of-date. You can determine if it is current by checking the Global_Dataset entry. For more information, see Optimizing State Information Passing.