Accessing and updating a configuration database from distributed physical locations within a process control system

摘要

A configuration database includes multiple databases distributed at a plurality of physical locations within a process control system. Each of the databases may store a subset of the configuration data and this subset of configuration data may be accessed by users at any of the sites within the process control system. A database server having a shared cache accesses a database in a manner that enables multiple subscribers to read configuration data from the database with only a minimal number of reads to the database. To prevent the configuration data being viewed by subscribers within the process control system from becoming stale, the database server automatically detects changes to an item within the configuration database and sends notifications of changes made to the item to each of the subscribers of that item so that a user always views the state of the configuration as it actually exists within the configuration database.