A DDL to subsystem compare is setting Labels and Comments to ' ' (blank).

Document ID : KB000007678
Last Modified Date : 14/02/2018
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Issue:

Analysis of a DDL to subsystem compare strategy is generating COMMENT and LABEL DDL that sets the text to blank.

For example:

COMMENT ON TABLE tbcreator.tbname IS ' '
            ;                                                               
LABEL   ON TABLE tbcreator.tbname IS ' '
            ;                       

The COMPARE FACILITY CHANGE ANALYSIS REPORT displays the following: 

------------ Table Column Changes --------------------
Attribute Status Value
--------- ----------- ----+----1----+----2----+----3--
NAME Currently: colname 
Changed To: (NOT CHANGED)
COMMENT Currently: current-comment-text 
Changed To:
LABEL Currently: current-label-text 
Changed To:                                    

Cause:

This is as a result of incomplete object DDL in the input DDL file. RC/Migrator is therefore detecting this as a change to the target definition of the object.

Resolution:

LABELs and COMMENTS are not considered objects. They are attributes of objects. So they are not handled in the same way as objects such as indexes or tables. The only way to stop attributes from being compared is using the ruleset.

COL_LABEL N
COL_COMMENT N

With the two column rules set to N, we tell RC/Migrator not to compare column labels or column comments, which means we keep the target values.

The need for setting these rules to 'N' can be avoided by ensuring that the input file includes the complete DDL of the objects that you want to compare.