Fields in the Database-Buffer-Pool report

The following figure is an example of a Database Buffer Pool report.

                   D A T A   B A S E   B U F F E R   P O O L
                                                                                        FIX PREFIX/BUFFERS           Y/Y
                                                                                        SUBPOOL ID                  O04K
                                                                                        SUBPOOL BUFFER SIZE         4096
                                                                                        TOTAL BUFFERS IN SUBPOOL    1000

                                                                          17:08:15           17:10:16

    NUMBER OF LOCATE-TYPE CALLS                                            1117674            1676213             558539
    NUMBER OF REQUESTS TO CREATE NEW BLOCKS                                      0                  0                  0
    NUMBER OF BUFFER ALTER CALLS                                            215874             322936             107062
    NUMBER OF PURGE CALLS                                                    25077              37454              12377
    NUMBER OF LOCATE-TYPE CALLS, DATA ALREADY IN OSAM POOL                  870306            1301187             430881
    NUMBER OF BUFFERS SEARCHED BY ALL LOCATE-TYPE CALLS                    1258247            1886843             628596
    NUMBER OF READ I/O REQUESTS                                             238165             360260             122095
    NUMBER OF SINGLE BLOCK WRITES BY BUFFER STEAL ROUTINE                        0                  0                  0
    NUMBER OF BLOCKS WRITTEN BY PURGE                                        95057             142413              47356
    NUMBER OF LOCATE CALLS WAITED DUE TO BUSY ID                               780               1297                517
    NUMBER OF LOCATE CALLS WAITED DUE TO BUFFER BUSY WRT                         0                  0                  0
    NUMBER OF LOCATE CALLS WAITED DUE TO BUFFER BUSY READ                        0                  0                  0
    NUMBER OF BUFFER STEAL/PURGE WAITED FOR OWNERSHIP RLSE                     178                261                 83
    NUMBER OF BUFFER STEAL REQUESTS WAITED FOR BUFFERS                           0                  0                  0
    TOTAL NUMBER OF I/O ERRORS FOR THIS SUBPOOL                                  0                  0                  0
    NUMBER OF BUFFERS LOCKED DUE TO WRITE ERRORS                                 0                  0                  0

The meaning of the various fields in the report is as follows:

FIX PREFIX/BUFFERS: This field indicates the fix options for the buffer prefix/data buffers for this subpool.
SUBPOOL ID: This field is a 4 character pool ID provided at subpool definition time.
SUBPOOL BUFFER SIZE: This field indicates the size, in bytes, of the buffers in this subpool.
TOTAL BUFFERS IN SUBPOOL: This field indicates the total number of buffers in this subpool.

On the following line are time entries that indicate the start trace and end trace times. The start trace and end trace fields tell you the time when the DB Monitor program was last started and stopped.

NUMBER OF LOCATE-TYPE CALLS: This field indicates the number of locate-type calls for this subpool.
NUMBER OF REQUESTS TO CREATE NEW BLOCKS: This field indicates the number of times a block had a segment inserted for the first time. When this happens, the block is marked as modified and must eventually be written back to the database.
NUMBER OF BUFFER ALTER CALLS: This field indicates the number of buffer alter calls for this subpool. This count includes NEW BLOCK and BYTALT calls.
NUMBER OF PURGE CALLS: This field indicates the number of purge requests for this subpool.
NUMBER OF LOCATE-TYPE CALLS, DATA ALREADY IN SUBPOOL: This field indicates the number of locate-type calls for this subpool where the data was already in an OSAM pool.
NUMBER OF BUFFERS SEARCHED BY ALL LOCATE-TYPE CALLS: This field indicates the number of buffers searched by all locate-type calls for this subpool.
NUMBER OF READ I/O REQUESTS: This field indicates the number of read I/O requests for this subpool.
NUMBER OF SINGLE BLOCK WRITES BY BUFFER STEAL ROUTINE: This field indicates the number of single block writes initiated by buffer steal routine for this subpool.
NUMBER OF BLOCKS WRITTEN BY PURGE: This field indicates the number of blocks for this subpool written by purge.
TOTAL NUMBER OF I/O ERRORS FOR THIS SUBPOOL: This field indicates the total number of I/O errors for this subpool.
NUMBER OF BUFFERS LOCKED DUE TO WRITE ERRORS: This field indicates how many buffers are currently frozen in storage because a permanent I/O error occurred when writing them to the database. When a write operation results in a permanent I/O error, the affected buffers are frozen in storage until the data set is closed or, in an online system, until the system is shut down. Once the data set is closed, or the online system shut down, the buffers are written to the log, and this number returns to 0.
NUMBER OF LOCATE CALLS WAITED DUE TO BUSY ID: This field indicates the number of locate calls for this subpool which waited due to busy ID.
NUMBER OF LOCATE CALLS WAITED DUE TO BUFFER BUSY WRT: This field indicates the number of locate calls for this subpool which waited due to buffer busy writing.
NUMBER OF LOCATE CALLS WAITED DUE TO BUFFER BUSY READ: This field indicates the number of locate calls for this subpool which waited due to buffer busy reading.
NUMBER OF BUFFER STEAL/PURGE WAITED DUE TO BUFFER BUSY READ: This field indicates the number of locate calls for this subpool which waited for ownership to be released.
NUMBER OF BUFFER STEAL REQUESTS WAITED FOR BUFFERS: This field indicates the number of buffer steal requests for this subpool which waited because no buffers were available to be stolen.