The system log file is automatically extended in response to the following two triggers.

Trigger 1:

HiRDB detects that the percentage of free area in a system log file has fallen below the warning value based on the function for monitoring the free area for system log files.

Trigger 2:

There is no swappable standby file to use when the current system log file becomes full.

When one of the triggers for automatically extending a system log file occurs, the message KFPS01391-I and a system log file status information file are output. For details about the system log file status information file, see 3.10.7 Outputting the system log file status information file (automatic extension facility).

When a system log file is automatically extended in response to Trigger 1, no warning message is issued and the scheduling of new transactions is not suppressed.

The method of automatically extending a system log file in response to each trigger is as follows.

In response to Trigger 1:

HiRDB sequentially extends the swappable standby files one by one. When all of the system log files to be extended have been extended once in response to triggers, the first round of automatic extension ends. The following figure provides an overview of automatic extension in response to Trigger 1.

Figure 3-8 Overview of system log file automatic extension (in response to Trigger 1)

Explanation

In response to Trigger 1, HiRDB sequentially extends the standby files. The size by which a standby file is extended each time is specified by the pd_log_auto_expand_size operand. The current file, unswappable standby files, and reserved files (including locked files) are excluded from extension.

In response to Trigger 2:

HiRDB extends the current file. The following figure provides an overview of automatic extension in response to Trigger 2.

Figure 3-9 Overview of system log file automatic extension (in response to Trigger 2)

Explanation

In response to Trigger 2, HiRDB extends the current file. The size by which the current file is extended each time is specified by the pd_log_auto_expand_size operand. Standby files and reserved files (including locked files) are excluded from extension.

When system log files are duplexed, both system log files in each file group are extended.

For details about HiRDB processing during automatic extension, see 3.10.3 HiRDB processing during automatic extension.

Even when the system log file automatic extension facility is being used, a system log file cannot be automatically extended when any of the following triggers occurs:

1. The disk containing the HiRDB file system area in which system log files are created has become full.
2. The capacity of a system log file has reached the upper limit for system log files (100 GB).
3. The capacity of a system log file has reached the extension upper limit specified by the pd_log_auto_expand_size operand.
4. An input/output error caused the system log file extension to fail.
5. A memory shortage caused the system log file extension to fail.
6. A lock segment shortage caused the system log file extension to fail.

Except in case 1, the system log file is prevented from being extended. For details about actions that the HiRDB administrator must take when system log files cannot be automatically extended, see 3.10.4 Actions to be taken by the HiRDB administrator when system log files cannot be automatically extended.