Format of VSAM buffer subpool statistics

Because there might be several buffer subpools for VSAM databases, the STAT call is iterative when requesting these statistics. If more than one VSAM local shared resource pool is defined, statistics are retrieved for all VSAM local shared resource pools in the order in which they are defined. For each local shared resource pool, statistics are retrieved for each subpool according to buffer size.

The first time the call is issued, the statistics for the subpool with the smallest buffer size are provided. For each succeeding call (without intervening use of the PCB), the statistics for the subpool with the next-larger buffer size are provided.

If index subpools exist within the local shared resource pool, the index subpool statistics always follow statistics of the data subpools. Index subpool statistics are also retrieved in ascending order based on the buffer size.

The final call for the series returns a GA status code in the PCB. The statistics returned are totals for all subpools in all local shared resource pools. If no VSAM buffer subpools are present, a GE status code is returned to the program.

VBASF

This function value provides the full VSAM database subpool statistics in a formatted form. The application program I/O area must be at least 360 bytes. Three 120-byte records (formatted for printing) are provided as two heading lines and one line of statistics. Each successive call returns the statistics for the next data subpool. If present, statistics for index subpools follow the statistics for data subpools.

The following diagram shows the data format.

                  BUFFER HANDLER STATISTICS
BSIZ NBUF RET RBA RET KEY ISRT ES ISRT KS BFR ALT   BGWRT SYN PTS
nnnK  nnn nnnnnnn nnnnnnn nnnnnnn nnnnnnn nnnnnnn nnnnnnn nnnnnnn
 
                VSAM STATISTICS POOLID: xxxx
   GETS  SCHBFR   FOUND   READS USR WTS NUR WTS ERRORS
nnnnnnn nnnnnnn nnnnnnn nnnnnnn nnnnnnn nnnnnnn  nn/nn

POOLID: ID of the local shared resource pool.
BSIZ: Size of the buffers in this VSAM subpool. In the final call, this field is set to ALL.
NBUF: Number of buffers in this subpool. In the final call, this is the number of buffers in all subpools.
RET RBA: Number of retrieve-by-RBA calls received by the buffer handler.
RET KEY: Number of retrieve-by-key calls received by the buffer handler.
ISRT ES: Number of logical records inserted into ESDSs.
ISRT KS: Number of logical records inserted into KSDSs.
BFR ALT: Number of logical records altered in this subpool. Delete calls that result in erasing records from a KSDS are not counted.
BGWRT: Number of times the background-write function was executed by the buffer handler.
SYN PTS: Number of Synchronization calls received by the buffer handler.
GETS: Number of VSAM GET calls issued by the buffer handler.
SCHBFR: Number of VSAM SCHBFR calls issued by the buffer handler.
FOUND: Number of times VSAM found the control interval already in the subpool.
READS: Number of times VSAM read a control interval from external storage.
USR WTS: Number of VSAM writes initiated by IMS.
NUR WTS: Number of VSAM writes initiated to make space in the subpool.
ERRORS: Number of write error buffers currently in the subpool or the largest number of write errors in the subpool during this execution.

VBASU

This function value provides the full VSAM database subpool statistics in a unformatted form. The application program I/O area must be at least 72 bytes. Eighteen fullwords of binary data are provided for each subpool:

Word: Contents
1: A count of the number of words that follow.
2-18: The statistic values in the same sequence as presented by the VBASF function value, except for POOLID, which is not included in this unformatted form.

VBASS

This function value provides a summary of the VSAM database subpool statistics in a formatted form. The application program I/O area must be at least 180 bytes. Three 60-byte records (formatted for printing) are provided.

The following diagram shows the data format.

DATA BASE BUFFER POOL:  BSIZE nnnnnnn  POOLID xxxx  Type x
  RRBA nnnnn RKEY nnnnn BFALT nnnnn NREC nnnnn SYN PTS nnnnn
  NMBUFS nnn VRDS nnnnn FOUND nnnnn VWTS nnnnn  ERRORS nn/nn

BSIZE: Size of the buffers in this VSAM subpool.
POOLID: ID of the local shared resource pool.
TYPE: Indicates a data (D) subpool or an index (I) subpool.
RRBA: Number of retrieve-by-RBA requests.
RKEY: Number of retrieve-by-key requests.
BFALT: Number of logical records altered.
NREC: Number of new VSAM logical records created.
SYN PTS: Number of sync point requests.
NMBUFS: Number of buffers in this VSAM subpool.
VRDS: Number of VSAM control interval reads.
FOUND: Number of times VSAM found the requested control interval already in the subpool.
VWTS: Number of VSAM control interval writes.
ERRORS: Number of permanent write errors now in the subpool or the largest number of errors in this execution.