3-66 IBM Informix OnLine Database Server Administrator’s Guide

Monitor Buffers

Monitor Buffers
Usethe tbstat -b,-X, and -B options to identify a specific user process that is
holding a resource that might be needed by another user process.
The tbstat -p option can help you assess performance as measured by the
percentage of cached reads and writes.
For monitoring information that describes the efficiency of the buffer pool,
refer topage 3-68 (buffer-pool activity).

tbstat -b

From the command line, executetbstat -b to obtain the following buffer
statistics:
■General buffer statistics (total number, number modified)
■Address of each user process currently holding a buffer
■Page numbers for those pages in currently held buffers
■Address of the first user process waiting for each buffer
You can compare the addresses of the user processes to the addresses that
appear in the tbstat -u display to obtain the process ID number.
Refer topage 7-82 for further information about the tbstat -b output.

tbstat -X

Executetbstat -X to obtain the same information as tbstat -b, along with the
completelist of all user processes that are waiting for buffers, not just the first
waiting process.
Refer topage 7-101 for further information about the tbstat -X output.