How To Fix HH045 - Database buffer write quality could be better (buffers too small?)

SAP Error Message - Details

• Message type: E = Error

• Message class: HH - (Long) text for check tool 'infcfgcheck'

• Message number: 045

• Message text: Database buffer write quality could be better (buffers too small?)

What causes this issue?

This is a single 'performance' check and therefore does not
describe a critical system status. It is neither necessary nor
time-critical to perform the steps described below, but they could
help improve the overall performance of your R/3 System.

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

The 'hit rate' of pages in the database buffer in percent is not
optimal for write accesses. A rate of at least 82% is considered to be
optimal. A better 'hit rate' can often be obtained by extending
the database buffer (thus reducing the 'displacement rate' of pages in
the buffer). On the other hand, the ONCONFIG parameter 'BUFFERS' should
not be increased if this is not necessary in order to keep the
use of Shared Memory (i.e. main memory) within reason.

System Response

How to fix this error?

Check the write quality of the database buffer regularly with
'onstat -p'. If the percent value is constantly below 82%, try
increasing the ONCONFIG paramter 'BUFFERS'. You can assume 20% of the
physical memory as a approximate value for the buffer size.
As user 'informix', edit file
'$INFORMIXDIR/etc/$ONCONFIG' ('BUFFERS' = number of pages).
CAUTION: The change will only become active when the database has
been started up.
Please also refer to Note 38307.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message HH045 - Database buffer write quality could be better (buffers too small?) ?

  The SAP error message HH045, which states "Database buffer write quality could be better (buffers too small?)", typically indicates that the database buffer is not optimally configured for the workload being processed. This can lead to performance issues, as the system may be spending too much time writing data to the database instead of processing it.
  Cause:
  
  Insufficient Buffer Size: The database buffer may be too small to handle the volume of data being processed, leading to frequent writes and increased I/O operations.
  High Write Activity: If the application is generating a high volume of write operations, the buffer may not be able to keep up, resulting in performance degradation.
  Configuration Issues: The database or SAP system may not be optimally configured for the current workload, leading to inefficient use of resources.
  Database Performance: Underlying database performance issues can also contribute to this error, such as slow disk I/O or contention for resources.
  
  Solution:
  
  Increase Buffer Size: Review and increase the size of the database buffer. This can often be done in the database configuration settings or through the SAP profile parameters.
  
  For example, in an SAP system, you can adjust the dbs/ntab parameter to increase the number of database buffers.
  
  
  Monitor and Analyze Workload: Use transaction codes like ST03N (Workload Analysis) and ST04 (Database Performance Analysis) to monitor the workload and identify bottlenecks.
  Optimize Database Configuration: Ensure that the database is configured optimally for the workload. This may involve tuning parameters specific to the database system being used (e.g., Oracle, SQL Server, etc.).
  Review Application Logic: Check if there are any inefficiencies in the application logic that could be causing excessive writes to the database.
  Database Maintenance: Perform regular database maintenance tasks, such as updating statistics, rebuilding indexes, and checking for fragmentation, to ensure optimal performance.
  Consult Documentation: Refer to the SAP Notes and documentation specific to your version of SAP and the database being used for any additional recommendations.
  
  Related Information:
  
  SAP Notes: Check for any relevant SAP Notes that may provide additional insights or specific recommendations for your version of SAP.
  Performance Monitoring Tools: Utilize SAP's performance monitoring tools to gain insights into system performance and identify areas for improvement.
  Database Documentation: Review the documentation for your specific database system for best practices on buffer management and performance tuning.
  
  By addressing the underlying causes and implementing the recommended solutions, you should be able to improve the database buffer write quality and enhance overall system performance.