In a CA-IDMS database, one function of the RESTRUCTURE utility is to add elements to existing network records, and to provide initial values for those fields. For COMP-3 unsigned fields, it may be important to ensure that the correct value will be stored in these fields.
In a CA-IDMS database, the RESTRUCTURE utility can be used to add new fields to existing network database records. As part of this process, the IDMSRSTC utility can be run to compare the old and new schema record definitions, and to generate syntax to create the new fields. This output will be in the form of IDMSRSTT FIELD statements, which will serve as part of the input to the RESTRUCTURE utility. However, all output generated by this schema compare utility should be examined and either changed if what has been generated is not what is desired; or should be corrected if it is not correct.
A Restructure can be performed in any IDMS environment on any operating system.
On the IDMSRSTT FIELD definition of a new COMP-3 field, the first operand coded should be a "new_field_value". In the case of a COMP-3 field, it is particularly important to review and verify this. That is because even though a COMP-3 field can be defined without a sign, it is by default a signed field in assembler. Therefore, the default initial value generated by IDMSRSTC for a COMP-3 field will always end with a 'C' in the sign digit. If user applications rely on having an 'F' in the sign position, then this must be manually assigned by changing the initial value generated by IDMSRSTC to contain an 'F' instead of the 'C', before that code is input to the RESTRUCTURE utility.
More details about the RESTRUCTURE utility as well as the process for running the IDMSRSTC utility can be found in the CA IDMS Utilities Guide.