Output Description

For each queue, onstat -R lists the number of buffers in the queue and the number and percentage of buffers that have been modified. You can interpret output from this option as follows:

#

shows the queue number. Each LRU queue is composed of two subqueues: an FLRU queue and a MLRU queue. (For a definition of FLRU and MLRU queues, see LRU queues in the shared-memory chapter of the IBM Informix: Administrator's Guide.) Thus, queues 0 and 1 belong to the first LRU queue, queues 2 and 3 belong to the second LRU queue, and so on.

f/m

identifies queue type. This field has four possible values:

f

Free LRU queue

In this context, free means not modified. Although nearly all the buffers in an LRU queue are available for use, the database server attempts to use buffers from the FLRU queue rather than the MLRU queue. (A modified buffer must be written to disk before the database server can use the buffer.)

F

Free LRU with fewest elements

The database server uses this estimate to determine where to put unmodified (free) buffers next.

m

MLRU queue

M

MLRU queue that a flusher is cleaning

length

tracks the length of the queue measured in buffers.

% of

shows the percent of LRU queue that this subqueue composes. For example, suppose that an LRU queue has 50 buffers, with 30 of those buffers in the MLRU queue and 20 in the FLRU queue. The % of column would list percents of 60.00 and 40.00, respectively.

pair total

provides the total number of buffers in this LRU queue.

Summary information follows the individual LRU queue information. You can interpret the summary information as follows:

dirty

is the total number of buffers that have been modified in all LRU queues.

queued

is the total number of buffers in LRU queues.

total

is the total number of buffers.

hash buckets

is the number of hash buckets.

buffer size

is the size of each buffer.

start clean

is the value of LRU_MAX_DIRTY.

stop at

is the value of LRU_MIN_DIRTY.