You can remove the data from a Citadel database using LabVIEW, Lookout or Measurement & Automation Explorer. This is a two step process:
- First you archive the data that you want to delete. When archiving, choose to delete this data from the original database. The archiving operation will move the data from your database to new database.
- The second step is to delete the new archived database. This removes the extra database that was created by the archive operation. Once the data has been archived you can remove the archived data by either deleting the database manually or by using file VIs from LabVIEW.
The document elaborates this process for Measurement & Automation Explorer, LabVIEW and Lookout separately
- Measurement & Automation Explorer: You must have Historical Data Viewer installed. It comes with Lookout 5.0 and LabVIEW DSC 6.1 and later.
To remove the historical data in Measurement & Automation Explorer, follow these steps:
- Under the Historical Data folder in Measurement & Automation Explorer, select the database that you want to remove data from.
- Right-click the database and select New View»Trace. This creates a trace view with the default name of New View under the database folder.
- On the Trace Attributes page, click on Add new traces. Select the traces you want to archive.
- Select a starting and stopping time.
- Right-click New View and select Archive.
- Enter a directory path to store the archived data.
- Check the Delete data from source database checkbox to delete the data from the source database.
- Click Start.
- Once it is complete, click Close.
- Right-click in the Trace Attributes window and choose Refresh. You will see that the data has been removed from the current database.
- LabVIEW Datalogging and Supervisor Control (LabVIEW DSC 6.1 and later)
Use the Archive Traces VI, Delete Traces VI, and Delete Database VI from the Historical Data palette to remove data from the data base. Be aware that deleting traces will permanently remove the data and it will be lost if it is not previously archived. If you delete traces and you find that the database size does not decrease, you may need to compact your database
. Before deleting a database, make sure that it is detached from your Citadel Univers
Use the CitadelControl object in the Logging category. The data member DeleteEnabled controls whether the data is deleted when it is archived.