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Analysis of problem transactions

To choose an effective backout strategy, you should first analyze the problem transactions.

The following figure Analyze Problem Transactions panel shows the task dialog panel for this action:

ANALYZE                    Analyze Problem Transactions 
Command ===>                                                                  
                                                                   SSID : DBR2  
Work ID . . : USER2.$$WORKID0008                                             
Description : USER2 2013-01-18 12.28.10 ANALYZE                             
                                                                                
To perform the analysis, specify Options 1, 2, and 3.                          
                                                                                
Select an Option. Then press Enter.                                            
                                                                                
Options . . . _   1. Specify Log Filter Criteria                                
                  2. Specify Time Frame and/or Input Source                     
                  3. Define Report and File Outputs                             
                  4. Define Log Mark                                            
                  5. Specify Run Time Options                                   
                                                                                
                  9. Work ID Options, JCL Generation

Default outputs for the Analyze Problem Transactions option include the Backout Integrity and Summary reports. These reports provide information to help you analyze and select a backout strategy. For example, you can specify a filter and time frame to select specific sets of transactions. Log Master generates an UNDO SQL output file. A Summary report of these transactions shows how many insert, update, and delete actions that the UNDO SQL output file includes. The Backout Integrity report displays selected changes affected by subsequent updates. This comparison of data can help you determine problems and potential solutions.

Under certain circumstances, you may have to decide whether you should apply UNDO SQL or REDO SQL to back out problem transactions. Consider generating both types of SQL files as output to an Analyze Problem Transaction job. You can use the Backout Integrity and Summary reports to compare the number and types of statements generated for each file type.

Note

In general, Log Master uses more resources to generate a Backout Integrity report than it does to generate other reports. Log Master can use more CPU time, more I/O time, and scan more log to generate a Backout Integrity report than you might anticipate based on your filter and time frame.

To get information about previously saved SQL output files, or to browse the contents of the SQL output files, from the Main Menu, select Previously Created Outputs. (For an example, see the figure 'SQL Dataset Information panel' in Output file definitions.)

Best Practice

BMC recommends that you select complete transactions, rather than updates to only some of the tables that are involved in the problem. Selecting complete transactions maintains the original transaction’s integrity. In addition, when generating UNDO SQL, include referential integrity updates to reverse the effects of cascading delete actions, or the nulling of foreign keys.

You might choose to execute generated SQL as a follow-up to performing a problem transaction analysis. In the analysis, you would generate reports and SQL for study, but not for execution. After the analysis, you can execute the SQL statements.

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