How To Fix SDBALM084 - Hit rate for the SQL data in the data cache in %

SAP Error Message - Details

• Message type: E = Error

• Message class: SDBALM - SAP DB and liveCache Alert Monitoring

• Message number: 084

• Message text: Hit rate for the SQL data in the data cache in %

Description
The system calculates and displays the hitrate since the last run of
the data collector. In the case of the first run of the data collector
after a restart of the instance or after the Alert Monitor is started,
the system does not display a hitrate.
Data Collector
<ZH>Collector B</>
(RZ20 -> SAP CCMS Technical Experts Monitors -> All Monitoring Contexts
,,-> <Name of the database connection> -> Collectors and Internals
-> Collectors -> Collector B)

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

Preset runtime interval of Collector B: 15 minutes

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message SDBALM084 - Hit rate for the SQL data in the data cache in % ?

  The SAP error message SDBALM084 indicates that the hit rate for the SQL data in the data cache is below an acceptable threshold. This message is part of the database performance monitoring in SAP, specifically related to the SQL data cache, which is used to store frequently accessed SQL statements to improve performance.
  Cause:
  The low hit rate in the SQL data cache can be caused by several factors, including:
  
  High Volume of Unique SQL Statements: If there are too many unique SQL statements being executed, the cache may not be able to store all of them, leading to a lower hit rate.
  Insufficient Cache Size: The size of the SQL data cache may be too small to accommodate the workload, causing frequent cache misses.
  Frequent Changes in Data: If the underlying data changes frequently, the cached SQL statements may become invalid, leading to a lower hit rate.
  Poorly Optimized Queries: Inefficient SQL queries that do not leverage the cache effectively can also contribute to a low hit rate.
  Database Configuration Issues: Incorrect database configuration settings can impact the performance of the SQL data cache.
  
  Solution:
  To address the SDBALM084 error and improve the hit rate for the SQL data cache, consider the following solutions:
  
  Increase Cache Size: If the cache size is too small, consider increasing it to accommodate more SQL statements. This can be done through database configuration settings.
  Optimize SQL Queries: Review and optimize the SQL queries being executed. Ensure that they are efficient and make use of indexes where appropriate.
  Monitor and Analyze SQL Statements: Use tools to monitor the SQL statements being executed and identify any that are causing excessive cache misses. Focus on optimizing these statements.
  Adjust Database Parameters: Review and adjust database parameters related to caching and memory allocation to ensure optimal performance.
  Regular Maintenance: Perform regular database maintenance tasks, such as updating statistics and rebuilding indexes, to ensure that the database is performing optimally.
  Review Application Logic: If the application is generating a high volume of unique SQL statements, consider reviewing the application logic to reduce the number of unique queries.
  
  Related Information:
  
  Transaction Codes: You can use transaction codes like ST02 (Tune Summary) and ST04 (Database Performance Analysis) to monitor and analyze the performance of the SQL data cache.
  SAP Notes: Check for relevant SAP Notes that may provide additional guidance or patches related to SQL data cache performance.
  Database Documentation: Refer to the documentation for your specific database (e.g., Oracle, SQL Server, HANA) for best practices on caching and performance tuning.
  
  By addressing the underlying causes and implementing the suggested solutions, you should be able to improve the hit rate for the SQL data in the data cache and resolve the SDBALM084 error.