6. DATA SOURCES › 6.5 ACCUMACC Roll-up Records

6.5 ACCUMACC Roll-up Records

Beginning with DB2 Version 8.1, the ACCUMACC zPARM can be
used to instruct DB2 to summarize accounting records for DDF
and RRSAF transaction records prior to writing to SMF.

To use this feature, an ACCUMACC threshold parameter is
specified in the range from 2 to 65535.  This threshold
represents the number of records that will be summarized
before a roll-up record is written.  The roll-up is done for
each end-user identifier, defined as the concatenation of
end-user ID, end-user transaction name, and end-user
workstation name.

The data element names representing these key data elements
are found in the DB2 User Activity (DB2DSU) file:

 - DSUEUTX  End User Transaction Name
 - DSUEUWN  End User Workstation Name
 - DSUEUID  End USERID

A related DB2 zPARM, ACCUMUID, permits customization of the
end-user fields used for summarization.  The following
combinations are permitted:

 - End user ID, transaction name, and workstation name.
 - End user transaction name.
 - End user workstation name.
 - End user ID and transaction name.
 - End user ID and workstation name.
 - End user transaction name and workstation name.

ACCUMACC and the CA MICS DB2 Analyzer
-------------------------------------
External access to mainframe based DB2 databases can result
in high volumes of DDF and RRSAF transactions.  ACCUMACC
offers relief via lower volumes of SMF data records, but with
some loss of information.

o Character Fields
  ----------------
  Character fields cannot be summarized.  In some cases, IBM
  stores the character field from the last accounting record
  summarized.  In other cases, character fields are left
  empty in the SMF data records.

o Numeric Fields
  --------------
  Most numeric fields representing counts are summarized
  correctly in the ACCUMACC roll-up records.  Fields that
  represent timestamp values and certain bit-map fields,
  however, cannot be accurately summarized.

In cases where data is unreliable or unavailable, it must be
interpreted differently due to ACCUMACC summarization.
CA MICS data dictionary element descriptions provide the
information necessary to understand the data element values
represented.  In cases where numeric data metrics are
unavailable with ACCUMACC summarization, CA MICS sets the
values to missing (.).

CA MICS file observations created from ACCUMACC roll-up
records are easily identified.  Data element Special
Transaction Type Identifier (DB2PTASK) is set to 'ACUMAC'
when the source record was an ACCUMACC roll-up record.

The following sections explain the impact of ACCUMACC on
several CA MICS DB2 Analyzer files.  Included is information
to assist you in understanding how well ACCUMACC is reducing
SMF record volume.

  1 - ACCUMACC and DB2 Region Level Files
  2 - ACCUMACC and Transaction Level Files