Home > ETL Best Practices > Use Checksum Computed Column for Daily Refreshing Rate Analysis

Use Checksum Computed Column for Daily Refreshing Rate Analysis

This is part of the table creation script that uses a computed column colChecksum. Column colChecksum uses SQL function Checksum() to create a check sum value for each row based on the field list that is passed to the Checksum() function.

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Do not expect SQL function Checksum to give you unique value for each unique row. Different row can have same check sum value. But you need not to worry though. For the refreshing rate analysis, you would use the natural key together with the check sum value to determine if any record needs to be refreshed or not.

Here is an example that compares the current data to previous data, using the natural key Hostname plus the check sum computed column.

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Categories: ETL Best Practices
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