Book Image

Oracle 10g/11g Data and Database Management Utilities

Book Image

Oracle 10g/11g Data and Database Management Utilities

Overview of this book

Does your database look complicated? Are you finding it difficult to interact with it? Database interaction is a part of the daily routine for all database professionals. Using Oracle Utilities the user can benefit from improved maintenance windows, optimized backups, faster data transfers, and more reliable security and in general can do more with the same time and resources.
Table of Contents (18 chapters)
Oracle 10g/11g Data and Database Management Utilities
Credits
About the Author
About the Reviewer
Preface

Time expression syntax


Prior to DBMS_SCHEDULE, the way to specify the repeating interval with the DBMS_JOB was pretty complex, and not very easy to read. The time expressions were PL/SQL expressions that resulted in a rigid schedule pattern. The syntax used by the Scheduler time is far more flexible and powerful, and, among many other features, the richness of the time expressions is one of the Scheduler's strengths.

The repeat interval

The repeat interval goes from as little as seconds, to years. The frequency can be defined seconds, minutes, hours, days, weeks, months, and years.

The syntax used to write time intervals can be specified either using a regular schedule or a combined schedule.

repeat_interval = regular_schedule | combined_schedule

Regular schedule

The regular schedule is composed of three main sections—the frequency definition, the interval, and the timing specification.

regular_schedule =
frequency_clause
[";" interval_clause]
[";" bymonth_clause]
[";" byweekno_clause]
...