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Analyzing data differences

The most common errors reported by DMF are data differences.

Data differences can occur for a variety of reasons, such as any of the following situations:

When DMF detects a difference in the data retrieved from VSAM and DB2®, diagnostic information is written to the job log. An example of the diagnostics follows:

Figure 1. DMF diagnostics for the data differences in batch programs
VIDSS227 DUALMODE ERROR FOR SUBSYS=VIDZ VSAM DDNAME=ENTITLV         
         RECORD DATA WAS NOT THE SAME AT OFFSET X"0036"              
VIDSS219 DUMP OF DB2 RECORD:                                         
VIDSS220 +0016 F0F0F0F0 F0F0F0F4 F1E4F4F1 E5F4F100 *000000041U41V41.*
VIDSS220 +0026 00004040 40404040 40404040 40404040 *..              *
VIDSS220 +0036 40404040 40404040 40404040 40404040 *                *
VIDSS220 +0046 40404040 40404040 40404040 40404040 *                *
VIDSS219 DUMP OF VSAM RECORD:                                        
VIDSS220 +0016 F0F0F0F0 F0F0F0F4 F1E4F4F1 E5F4F100 *000000041U41V41.*
VIDSS220 +0026 00004040 40404040 40404040 40404040 *..              *
VIDSS220 +0036 C9C9C9D5 D5D5C6C6 C6404040 40404040 *IIINNNFFF       *
VIDSS220 +0046 40404040 40404040 40404040 40404040 *                * 

The diagnostics show that a difference in the data was detected at hexadecimal offset x'0036': the value in the record retrieved from VSAM is x'C9C9C9D5D5D5D5C6C6C6', and the value in the record built by CICS® VT from DB2 is spaces.

Convert the hexadecimal offset X'0036' to decimal, then add 1 to get the position of the field in the data set mapping. In the example in Figure 1, the field position is 55. Review the field mapping at position 55, and if the field is build by an FBE, review the FBE code.

DMF dumps 32 bytes of data before and after the error, shown as message number VIDSS220. The application program is abnormally terminated with a U3139 abend code.


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Timestamp icon Last updated: Monday, 10 February 2014


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