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All logical-log files have one of the following three
status flags in the first position: Added (A), Free (F), or Used
(U). Descriptions
of all the individual logical-log status flags follow.
- Status Flag
- Description
- Added (A)
- A logical-log file has an added status
when it is newly added. The logical-log file does not become available
for use until you complete a level-0 backup of the root dbspace.
- Free (F)
- A logical-log file is free when it
is available for use. A logical-log file is freed after it is backed
up, all transactions within the logical-log file are closed, and
the oldest update stored in this file is flushed to disk.
- Used (U)
- A logical-log file is used when it
is still needed by the database server for recovery (rollback of
a transaction or finding the last checkpoint record).
- Backed-Up (B)
- A logical-log file has a backed-up status
after it has been backed up.
- Current (C)
- A logical-log file has a current status
if the database server is currently filling the log file.
- Last (L)
- A logical-log file has a status of last if
it contains the most recent checkpoint record in the logical log.
This file and subsequent files cannot be freed until the database
server writes a new checkpoint record to a different logical-log
file.
- Deleted (D)
- This flag indicates that a logical log has been dropped, but
its space has not been freed. The disk space of deleted logical
logs is freed after a level-0 archive has been performed on all
dbspaces. After a deleted logical log's disk space has
been freed, it is removed from the logical log list.
Table 26 shows the possible
log-status flag combinations.
Table 26. Logical-Log Status Flags
| Status Flag |
Status of Logical-Log File |
| A------ |
Log has been added since the last level-0 storage-space
backup. Not available for use. |
| F------ |
Log is free. Available for use. |
| U |
Log has been used but not backed up. |
| U-B---- |
Log is backed up but still needed for recovery. |
| U-B---L |
Log is backed up but still needed for recovery.
Contains the last checkpoint record. |
| U---C |
Log is the current logical-log file. |
| U---C-L |
Log is the current logical-log file. It contains
the last checkpoint record. |
Tip:
Typically a logical-log file has a status of F for
only a very brief time before it is reused.
To find out the status of a logical-log
file, use the methods explained in Monitoring the
Logical Log for Fullness.
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