This component allows you to perform incremental data loads. Data records already extracted by previous executions of the project will be skipped. The incremental load is controlled by an attribute containing ascending values, the Ascending Index.
During simulation of a project, you can manipulate the value of the Ascending Index with the Load Index Value property.
The value of the Load Index is not updated within the Sybase IQ ETL Repository when the project is executed during simulation.
To perform an incremental load using the stored value
of the Ascending Index, projects using this component must be executed
within a job or schedule.
Use this component if you need to track source changes on a regular basis. The loading time can be significantly reduced only if the delta of the day has to be transferred, instead of loading very large tables or views on a daily basis.
Enter the Connection Parameters as described in “Entering database connection parameters”.
Select the Ascending Index attribute from the list of database objects.
Select an attribute with values that increase whenever data is changed or added to the source, such as an auto incremental ID or a modification date. It is not required to have this attribute indexed on the database schema level; however, for performance reasons Sybase recommends that you create an index.
Enter a Query for the incremental load.
The selection criteria in the WHERE clause needs to be qualified using the predefined variable LoadIndex. Enclose the LoadIndex with square brackets, because it is evaluated before the query is sent to the database, for example:
SELECT * FROM SALES WHERE SA_DELIVERYDATE > '[LoadIndex]' ORDER BY SA_DELIVERYDATE
Quote characters differ between database systems. On
Microsoft Access databases, use # for datetime values.
To enter required properties