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Database trigger. A database trigger is procedural code that is automatically executed in response to certain events on a particular table or view in a database. The trigger is mostly used for maintaining the integrity of the information on the database. For example, when a new record (representing a new worker) is added to the employees table ...
Log trigger. In relational databases, the log trigger or history trigger is a mechanism for automatic recording of information about changes inserting or/and updating or/and deleting rows in a database table . It is a particular technique for change data capturing, and in data warehousing for dealing with slowly changing dimensions .
If the data is being persisted in a modern database then Change Data Capture is a simple matter of permissions. Two techniques are in common use: Tracking changes using database triggers; Reading the transaction log as, or shortly after, it is written. If the data is not in a modern database, CDC becomes a programming challenge.
A database trigger is like a stored procedure that Oracle Database invokes automatically whenever a specified event occurs. It is a named PL/SQL unit that is stored in the database and can be invoked repeatedly. Unlike a stored procedure, you can enable and disable a trigger, but you cannot explicitly invoke it.
Event condition action (ECA) is a short-cut for referring to the structure of active rules in event-driven architecture and active database systems. Such a rule traditionally consisted of three parts: The event part specifies the signal that triggers the invocation of the rule. The condition part is a logical test that, if satisfied or ...
PostgreSQL supports a binary communication protocol that allows applications to connect to the database server. The protocol is versioned (currently 3.0, as of PostgreSQL 7.4) and has a detailed specification. [48] The official client implementation of this communication protocol is a C API, libpq. [49]
Event-driven programming is the dominant paradigm used in graphical user interfaces applications and network servers. In an event-driven application, there is generally an event loop that listens for events and then triggers a callback function when one of those events is detected. Event-driven programs can be written in any programming ...
Active database. In computing, an active database is a database that includes an event-driven architecture (often in the form of ECA rules) that can respond to conditions both inside and outside the database. Possible uses include security monitoring, alerting, statistics gathering and authorization. [1] Most modern relational databases include ...