onstat -l command: Print physical and logical log information

Use the onstat -l command to display information about the physical logs, logical logs, and temporary logical logs.

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Syntax:

>>-onstat-- -l-------------------------------------------------><

Example Output

Figure 1. onstat -l command output
Physical Logging
Buffer bufused  bufsize  numpages numwrits pages/io
  P-1  0        16       716      55       13.02
      phybegin         physize  phypos   phyused  %used   
      1:263            500      270      0        0.00    

Logical Logging
Buffer bufused  bufsize  numrecs  numpages numwrits recs/pages pages/io
  L-3  0        16       42169    2872     1043     14.7       2.8     
        Subsystem    numrecs  Log Space used
        OLDRSAM      42169    4436496       

address  number   flags    uniqid   begin                size     used    %used
a517f70  1        U-B----  1        1:763                 500      500   100.00
a517fb0  2        U-B----  2        1:1263                500      500   100.00
a40daf0  3        U-B----  3        1:1763                500      500   100.00
a40db30  4        U-B----  4        1:2263                500      500   100.00
a40db70  5        U-B----  5        1:2763                500      500   100.00
a40dbb0  6        U---C-L  6        1:3263                500      372    74.40
a40dbf0  7        A------  0        1:3763                500        0     0.00
a40dc30  8        A------  0        1:4263                500        0     0.00
 8 active, 8 total

Output description for the physical log files

The first section of the display describes the physical-log configuration:
buffer
Is the number of the physical-log buffer
bufused
Is the number of pages of the physical-log buffer that are used
bufsize
Is the size of each physical-log buffer in pages
numpages
Is the number of pages written to the physical log
numwrits
Is the number of writes to disk
pages/io
Is calculated as numpages/numwrits

This value indicates how effectively physical-log writes are being buffered.

phybegin
Is the physical page number of the beginning of the log
physize
Is the size of the physical log in pages
phypos
Is the current position in the log where the next log-record write is to occur
phyused
Is the number of pages used in the log
%used
Is the percent of pages used
The second section of the onstat -l command output describes the logical-log configuration:
buffer
Is the number of the logical-log buffer
bufused
Is the number of pages used in the logical-log buffer
bufsize
Is the size of each logical-log buffer in pages
numrecs
Is the number of records written
numpages
Is the number of pages written
numwrits
Is the number of writes to the logical log
recs/pages
Is calculated as numrecs/numpages

You cannot affect this value. Different types of operations generate different types (and sizes) of records.

pages/io
is calculated as numpages/numwrits

You can affect this value by changing the size of the logical-log buffer (specified as LOGBUFF in the ONCONFIG file) or by changing the logging mode of the database (from buffered to unbuffered, or vice versa).

The following fields are repeated for each logical-log file:
address
Is the address of the log-file descriptor
number
Is logid number for the logical-log file

The logid numbers might be out of sequence because either the database server or administrator can insert a log file in-line.

flags
Provides the status of each log as follows:
A
Newly added (and ready to use)
B
Backed up
C
Current® logical-log file
D
Marked for deletion

To drop the log file and free its space for reuse, you must perform a level-0 backup of all storage spaces

F
Free, available for use
L
The most recent checkpoint record
U
Used
uniqid
Is the unique ID number of the log
begin
Is the beginning page of the log file
size
Is the size of the log in pages
used
Is the number of pages used
%used
Is the percent of pages used
active
Is the number of active logical logs
total
Is the total number of logical logs

Output description for temporary logical log files

The database server uses temporary logical logs during a warm restore because the permanent logs are not available then. The following fields are repeated for each temporary logical-log file:
address
Is the address of the log-file descriptor
number
Is logid number for the logical-log file
flags
Provides the status of each log as follows:
B
Backed up
C
Current logical-log file
F
Free, available for use
U
Used
uniqid
Is the unique ID number of the log
begin
Is the beginning page of the log file
size
Is the size of the log in pages
used
Is the number of pages used
%used
Is the percent of pages used
active
Is the number of active temporary logical logs

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