Automatic Merging and Purging of a Transaction Database

Facilities are available for automatically merging and purging each transaction database, in order to reduce its size and, consequently, improve its efficiency.

The principle of operation is that the system administrator can set rules that determine how long successful commands and/or failed commands can remain in the transaction database. At regular intervals, set by the administrator, the system deletes the expired commands, merges the database to a new file, deletes the existing file and then copies the merged file to the original filename.

As with all databases, the merging of a transaction database can be carried out only when no other users are currently accessing it.

The procedure for initiating automatic merging and purging and setting the rules is in the AVEVA Global User Guide.

The Global User Guide also contains information on manually merging and purging databases.