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This routine selects duplicates from the corresponding Change log table of extractor's InfoProvider, based on the semantic key that is also present in the underlying GLUE table. This means, that only fields of InfoProvider, that are also specified in the target GLUE table will be used in selection. The semantic key is then used in group by clause to determine duplicate entries. In case some key fields of the InfoProvider are omitted, multiple records of the Change log table will be evaluated as duplicates. Also, recordmode parameter, specified in the delta is taken into account and used in the where clause. This means, that the routine searches for duplicates within records satisfying recordmode selection in delta parameters. You can find more information about the Change log delta type in the chapter Changelog Change log delta.
The duplicates are then stored in an internal table together with their frequency. When the extraction is running, the routine checks how many times the record with the same semantic key occurred and skips the whole record in case it is not the last one. The last record is considered to be the most actual record and is transferred. The routine reads duplicates only once when the first line of a particular activation request is being transferred.
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