HiRDB stores date and time information within system log files, status files, and dictionaries for use during operations such as HiRDB restart. Date and time information is also stored in the work files of various utilities for use in several types of checking. Therefore, if you change the time used by the OS, you must make sure that the change will not affect the date and time information held by HiRDB. The effects of a change in the time used by the OS are described below, and related notes are provided.

When the time is set forward

Statistical information might not be correctly displayed, and the time display within messages might not be updated for a certain period of time.

Note that correct operation cannot be guaranteed if the date and time information is modified during HiRDB startup. Also, be aware of the restrictions specific to individual OSs.

When the time is moved back

Various problems might occur, including a restart failure, invalid database recovery, and unreasonable system wait time. Since moving the time back incorrectly might cause these problems, be sure to follow the procedures described in this section.

This section explains cases that require special attention when the time is moved back.

Organization of this section

9.12.1 Methods for moving the time back

9.12.2 Moving the time back using method 1

9.12.3 Moving the time back using method 2

9.12.4 Restoring the database using method 2 in the event of an error occurrence after the time was moved back

9.12.5 Restrictions on using method 2 to move back the time

9.12.6 Notes on using method 2 to move back the time