DataMigrator Management Problem Resolution

Situational errors sometimes occur in environments with complex iWay configurations or multiple users. The list below is meant to provide you with error messages similar to what you may encounter, and offer you resolutions such as you may find in DataMigrator. Each message is characterized by a single symptom, followed by an explanation or references to other materials.

Unique Constraint Error... Duplicate keys not permitted... or similar error for any of the relational database targets. DataMigrator has duplicate values in its extracted answer set, and there is a unique key on the table. For new targets, a unique key value may need to be specified in the Target Setup window. For existing targets, another column may need to be added to a concatenated key.

This error may also be caused by the retrieval mechanism: the use of the DISTINCT operator in the SQL command may really be the desired result (more rows than expected are being retrieved), or the source data may be a complex hierarchy or join that is creating duplicate rows. See the usage notes for your specific data target.

Format errors caused by dirty or invalid data. Legacy data is not always consistent in format and type. Older systems may have stored standard internal packed numbers for revenue figures but handled special logic conditions by inserting characters or low-values as needed by the application program. These issues often require handling with DEFINEs in the synonym at the source. There is a complete set of subroutines to handle various bit and byte oddities in your host information. For more information see Designing a Data Flow, and the appropriate FOCUS documentation for your platform. Problems of this type usually make themselves known through data exceptions and other error conditions (these would display in the ETL log). Depending on the data type combinations, they may also result in rejected records or a misinterpretation of missing data.

Confusing answer set; too many rows as the result of a Cartesian product. The rules of SQL control the join process for the source data to DataMigrator. Many-to-many joins result in a Cartesian product. This may be what the warehouse requires, but very often it is confusing because it results in additional rows being generated. The Cartesian product may also result from the extraction of columns that cross two paths of a multi-path legacy hierarchy. If this occurs, reduce the number of joins, and/or access only one path of a complex hierarchy. For details on the Cartesian product, see the appropriate iWay Server documentation for your platform.


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