IZ21727: WHEN RUNNING THE DBLOAD, EACH SUBSEQUENT LOAD GETS PROGRESSIVELY SLOWER THAN THE PRIOR LOADS TO THE POINT OF HOURS TO LOAD.

APAR status

• Closed as fixed if next.

Error description

• When running the DBLoad, each subsequent load gets progressively
  slower.  Initial loads are reasonably fast, but the additional
  loads become much slower each day.  This only occurs at
  installations with an extremely large amount of data.   This has
  occurred at a single customer that was loading approximately 5
  to 7 million Detail records per day.  This is
  dramatically beyond the recommended amount of data to be loaded.
  

Local fix

• This occurs because there is a duplicate load check at the
  beginning of each load.  This duplicate check evaluates against
  the data that is already loaded in the database.  The Summary
  check is fast, but the Detail check will run slowly in a very
  large database.
  
  Turning off the Detail Duplicate check will not improve the
  performance of the load.
  
  Because this only occurs on a highly unusual amount of data,
  there are a few steps that should be performed first:
  
  1) Evaluate the aggregation scheme with the data being loaded.
  Volumes in the 4 million record range are probably not being
  aggregated correctly.  Refer to the documentation for the
  platform where the data is being accumulated for information on
  how to improve aggregation.
  
  2) Evaluate whether the data needs to be captured as frequently.
   Snapshot collectors like DCollect on the mainframe, WinDisk on
  Windows and UNIX Filesystem on UNIX/Linux may only need to
  create one snapshot per month or week.  Snapshots of every day
  will create a very large amount of data.
  
  3) Evaluate the retention of the Detail data.  Since this issue
  only occurs on Detail data and not Summary data, there should be
  consideration for how long the Detail data is retained.   Some
  customers keep it for as short as one month because of volumes,
  but most will not keep more than one year.  Summary data can
  normally be kept for years or longer.
  

Problem summary

• When running the DBLoad, each subsequent load gets progressively
  slower.  Initial loads are reasonably fast, but the additional
  loads become much slower each day.  This only occurs at
  installations with an extremely large amount of data.   This has
  occurred at a single customer that was loading approximately 5
  to 7 million Detail records per day.  This is
  dramatically beyond the recommended amount of data to be loaded.
  

Problem conclusion

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Fix information

Applicable component levels

• R710 PSY

     UP