Performance implications for triggers

In many situations, triggers can improve performance slightly because of the reduction in the number of messages passed from the client to the database server.

For example, if the trigger fires five SQL statements, the client saves at least 10 messages passed between the client and database server (one to send the SQL statement and one for the reply after the database server executes the SQL statement). Triggers improve performance the most when they execute more SQL statements and the network speed is comparatively slow.

These operations cause only a slight performance impact that can be offset by the decreased number of messages passed between the client and the server.

However, triggers executed on SELECT statements have additional performance implications. The following sections explain these implications.