Purge Deleted Records

Associated with: Data Tables

Security permission required to access this pick action: Configure

Use the Purge Deleted Records pick action to purge the deleted records from a Data Table in order to reduce the size of the associated file and the memory used by the Data Table in the server(s). This will also reduce the amount of data that requires synchronizing between partners in a hot-standby system.

The size of the Data Table is automatically reduced if records are deleted from the end of the Data Table. However, if you delete records from the middle of the Data Table, they are not purged from the memory but will be reused when a new record is inserted.

The Status display of the Data Table shows the Record Count, Record Size, Table Size and the Deleted Record Count. You can analyze this information to determine whether or not to purge the deleted records.

Select the Purge Deleted Records pick action to display the Purge Deleted Records window and enter a required time limit.

• Time Limit (ms)—Specify the maximum amount of time, in milliseconds, that Geo SCADA Expert will spend purging deleted records from the Data Table. You can enter a time limit from 1 millisecond to 5000 milliseconds inclusive.

  Any deleted records that are not purged once this time limit expires will remain in the Data Table. However, you can repeat the purging process until all of the deleted records have been purged.

  The database is locked during the defined time limit while the deleted records are being purged. You might want to limit the maximum duration of each purge operation to minimize its impact on the system.

Select the OK button on the Purge Deleted Records window to confirm the time limit and enable the deleted records to be purged within the defined time limit.

The number of deleted records that are purged depends on the defined time limit. If the Data Table has indexed columns, purging the deleted records is slower and therefore fewer records might be purged within the defined time limit.

After purging the deleted records during the defined time limit, you can analyze the Status display of the Data Table to determine whether or not to repeat the process in order to purge the outstanding deleted records.

The Event Journal records the number of deleted records that have been purged along with the total number of deleted records. This also enables you to determine whether or not to repeat purging the outstanding deleted records.