6. DATA SOURCES › 6.5 ACCUMACC Roll-up Records › 6.5.1 ACCUMACC and DB2 Region Level Files

6.5.1 ACCUMACC and DB2 Region Level Files

The DB2 System Activity (DB2DSY) file is built from
interval records generated at the DB2 region level.
Included in the file are four data elements that count
the number of DDF and RRSAF ACCUMACC records written for
the region over the time interval represented by the
CA MICS file observation:

  DSYACFTQ - ACCUMACC Count: Failure to Qualify
  DSYACSTR - ACCUMACC Count: Storage Exceeded
  DSYACSTL - ACCUMACC Count: Staleness
  DSYACUTR - ACCUMACC Count: Threshold Exceeded

The first data element, DSYACFTQ, quantifies the number of
DDF and RRSAF transaction records that were written
unsummarized because one or more of the summarization key
fields was null.

The other three data elements quantify the number of roll-up
records written.  The most common reason that a roll-up
record is written is because the ACCUMACC threshold value was
exceeded (DSYACUTR).

The other two reasons, staleness and storage exceeded, mean
that a decision was made to write the roll-up record prior to
summarizing the amount of records specified by the ACCUMACC
threshold value.

By analyzing DSYACUTR and knowing your ACCUMACC threshold
value, you can determine SMF record reduction by DB2 region.

For example, if your ACCUMACC threshold is 10 and DSYACUTR
has a value of 1000 in a CA MICS observation, you know that
without ACCUMACC, the region would have written 10,000 DDF
and RRSAF transaction records, but instead, they were
consolidated into 1000 roll-up records, a reduction of 9,000
SMF records over the time period represented by the DB2DSY
file observation.