Introduction to scheduling and event handling

Many database administration tasks are best carried out systematically. For example, a regular backup procedure is an important part of proper database administration procedures.

You can automate routine tasks in Sybase IQ by adding an event to a database, and providing a schedule for the event. Whenever one of the times in the schedule passes, a sequence of actions called an event handler is executed by the database server.

Database administration also requires taking action when certain conditions occur. For example, it may be appropriate to e-mail a notification to a system administrator when a disk containing the transaction log is filling up, so that the administrator can handle the situation. These tasks can be automated by defining event handlers for one of a set of system events.

Chapter contents

This chapter contains the following material:

An introduction to scheduling and event handling (this section).

Concepts and background information to help you design and use schedules and event handlers:

“Understanding schedules”.

“Understanding events”.
A discussion of techniques for developing event handlers:
- “Developing event handlers”.
Internals information:
- “Schedule and event internals”.
Step by step instructions for how to carry out automation tasks.
- “Scheduling and event handling tasks”.

Questions and answers

To answer the question...	Consider reading...
What is a schedule?	“Understanding schedules”
What is a system event?	“Understanding events”
What is an event handler?	“Understanding event handlers”
How do I debug event handlers?	“Developing event handlers”
How does the database server use schedules to trigger event handlers?	“How the database server checks for scheduled times”
How can I schedule regular backups?	For an example, see “Understanding schedules”
What kind of system events can the database server use to trigger event handlers?	“Understanding events” “CREATE EVENT statement” in Chapter 6, “SQL Statements” of the Sybase IQ Reference Manual
What connection do event handlers get executed on?	“How event handlers are executed”
How do event handlers get information about what triggered them?	“Developing event handlers” “EVENT_PARAMETER function [System]” in Chapter 5, “SQL Functions” of the Sybase IQ Reference Manual