The DB2 tables must be loaded into the Knowledge Base with direct access. Then, during the masking or subsetting process, you can get the data from the backup obtained by image copy instead of the production table.
To obtain information from the image COPY, create a process identifier with the appropriate access type as described in the Front End Guide. In the following example, we assume the process identifier is DB2IC.
Before beginning the extraction or masking phase, you must execute the synchronization phase, to load the information concerning the image copies into Data Express.
Then, the name of the image copies data set must be inserted in the field UNLINPNAM of the data store HSDCHFIL (This information is specified in the File Name data element in the Unload Input File Properties section of the Elaboration properties window of the Work with Method area in Data Subset Extraction ) so the process can read the correct image copy as input file. (For more information, see the section Window Contents in the chapter Work with MethodElaboration Properties in the Subset Extraction Guide.)
To do this, use the exit routine UTERTIC (that must be customized to obtain the name of the image copies matching your environment) or use a query such as the following:
UPDATE KBAIMD.HSDCHFIL A SET UNLINPTYP = 'SEQ', PROCIDINP = 'DB2IC', UNLINPNAM = ( SELECT DSNAME FROM KBAIMD.HSURDICP B, KBAIMD.HSURDFIL D WHERE D.MCRECID = 1 AND D.FILRECID = A.FILRECID AND D.TSNAME = B.TSNAME AND D.DBNAME = B.DBNAME AND B.DSNUM < 2 AND B.ICDATE = '050319') WHERE A.MCRECID = 1 AND A.METHOD = 'PRIVACY1' AND EXISTS ( SELECT DSNAME FROM KBAIMD.HSURDICP C, KBAIMD.HSURDFIL E WHERE E.MCRECID = 1 AND E.FILRECID = A.FILRECID AND E.TSNAME = C.TSNAME AND E.DBNAME = C.DBNAME AND C.DSNUM < 2 AND C.ICDATE = '050319')
This query must be updated to change the owner of the tables HSDCHFIL, HSURDICP, and HSURDFIL in accordance with the parameters specified during the installation of Data Express.
Additionally, instead of using the value '050319' in the fields ICDATE, you must indicate the date of the image copy from which the process must read the data; instead of 'PRIVACY1' in the field METHOD, you must indicate the name of the method that must be executed, and instead of '1' in the field MCRECID, the progressive number associated with the Machine ID and the Company present in the method must be indicated.
After inserting the name of the image copy, the job Create Data Changer (for data masking) or the job Create Extraction Job (for data subsetting) can be executed. Both these jobs automatically generate a JCL that, starting from the image copy, unloads the information about the DB2 tables and the data into a temporary flat file that will be deleted at the end of the job. After this first step, the masking or subsetting program is submitted.
A similar process can be applied to the backups of the DB2 tables obtained by the unload utility of CA in VARIABLE, FIX, or COMMA SEPARATED format.