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Customizing - History Tables

Use the following parameters to customize the selected data source before cloning.

Configuration file parameters are included below with the following_font.

Data set history tables

Parameter: history_tables

These buttons define the initial values of two data set property bits, which we show as History Tables (None, Save History, History Only). You can override a setting for individual data sets by changing the setting in the data set properties page.

  • None: No history tables are created.

  • Save history: Creates normal and history tables in the DATATABLES Client control table. The normal table replicates the host data set. The history table contains a record for every update, which includes the update type, the data for the update record, and one or more columns used to maintain the order in which the updates occurred. For the SQL Server Client, the IDENTITY column is ideally suited for this purpose. A data warehouse can receive the synchronized clone from the normal table first. History tables use the original table name with a "_h" appended to it. After periodically importing the history table into the data warehouse, the history table can be purged.

  • Save history only: Creates only history tables. These tables receive cloned data and updates, in addition to records of the updates. The normal data table is not created or populated.

Options

Enable dynamic history

Parameter: enable_dynamic_hist

When enabled, history tables are added without recloning all of the affected data sets. You can specify the default history columns from the Customizing User Columns Section Two configuration page. Once the changes have been saved run a Redefine with options command from the Advanced button dropdown for the data source, and select the Redefine all data sets (-R) option. When the command completes, you'll need to run a Reorganize command to create the history tables and their indexes.

Inhibit Drop

Parameter: inhibit_drop_history

Prevents the Databridge Client from inadvertently dropping history tables during a clone, process, or drop command.

This is a safeguard to prevent an unrecoverable error. If you drop tables, it's recommended that you re-enable this option when you restart the Client.