Analysis parameter modification

Data Express includes a function that recognizes the file record image automatically. This function – together with the possibility of analyzing the COBOL and PL/I copies – lets you automatically associate the data store with the copybook describing it.

The applied algorithms are based on statistical analysis of the information. The information included in the data stores is analyzed to indicate the type of data included in each byte.

The analysis algorithms are based on parameters, which can be modified to meet the specific requirements of your database.

The analysis parameters include:

Analysis Option

Indicates the conditions under which a data store must be analyzed. For example:

• Perform the analysis only if the data store has not been analyzed.
• Perform the analysis if the data store has been analyzed but not associated.
• Perform the analysis even if the data store has already been analyzed and associated.

Number of Records

Indicates the number of records to analyze to identify the record image. The larger the number of analyzed records, the more accurate is the recognized record image.

Note: If the number of records to analyze is increased, the time required for the processing increases as well. The default value proposed is normally an acceptable compromise. In many cases, the different data elements included in the data stores may contain null values, such as a low-value, blank value, or all 0 or 9 digits. As a result, we recommend you increase the value of the Number of Records parameter to allow the analysis of a significant number of values.

Sample Data

Indicates whether to perform the analysis of the first n records of the data store (leaving the option blank), or to sample the records to be processed evenly within the data store.

Note: Record sampling increases the time required for processing, but we recommend record sampling for those data stores, which include many non-valued data elements within the first n records.

Copy Association

Indicates whether or not to associate the data store directly with the copybook describing its trace. The association algorithm will only be executed on copybooks analyzed until the copybook association is run. Therefore, we recommend you use this option only when the whole packet of copybooks belonging to the application has been analyzed.

Tolerance

Specifies a percentage of tolerance between the length of the data store layout and that of the copybook describing it.

Note: If you set this parameter to 0 (zero), these length values must coincide. Setting a tolerance to a value different from zero may be useful when ‘FILLER’ fields involving the use of a copybook layout longer than the data store layout are used in the copybook.

DB2 Date External Format

Specifies the format of the DB2 DATE field. This information is required during verification of values outside a validity range or in the identification of special values.

Note: During analysis, default values can be modified temporarily.