How To Fix SMMSS_ALERTS024 - Procedure cache hit ratio of &1% could be improved

SAP Error Message - Details

• Message type: E = Error

• Message class: SMMSS_ALERTS - Message class for MSSQL rz20 messages

• Message number: 024

• Message text: Procedure cache hit ratio of &1% could be improved

Self-Explanatory Message

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Smart SAP Assistant

• What is the cause and solution for SAP error message SMMSS_ALERTS024 - Procedure cache hit ratio of &1% could be improved ?

  The SAP error message SMMSS_ALERTS024 indicates that the procedure cache hit ratio is lower than expected, which can lead to performance issues in your SAP system. The procedure cache is used to store the compiled execution plans of SQL statements, and a low hit ratio suggests that the system is frequently recompiling SQL statements instead of reusing existing execution plans.
  Cause
  The low procedure cache hit ratio can be caused by several factors, including:
  
  High SQL Statement Variability: If your application generates a large number of unique SQL statements, the procedure cache may not be able to store all of them, leading to frequent recompilation.
  Insufficient Memory Allocation: If the memory allocated to the procedure cache is too small, it may not be able to hold all the necessary execution plans.
  Frequent Changes in Database Schema: Changes in the database schema can invalidate existing execution plans, causing them to be recompiled.
  Poorly Optimized SQL Queries: Inefficient SQL queries can lead to a higher number of unique execution plans being generated.
  Database Configuration Issues: Incorrect database configuration settings can also impact the procedure cache hit ratio.
  
  Solution
  To improve the procedure cache hit ratio, consider the following solutions:
  
  Increase Memory Allocation: Increase the memory allocated to the procedure cache. This can be done by adjusting the database configuration parameters related to memory allocation.
  Optimize SQL Queries: Review and optimize SQL queries to reduce variability. Use parameterized queries where possible to allow for better reuse of execution plans.
  Use Bind Variables: If applicable, use bind variables in your SQL statements to reduce the number of unique SQL statements generated.
  Monitor and Analyze SQL Performance: Use tools like SQL trace or performance analysis tools to identify poorly performing queries and optimize them.
  Review Database Configuration: Ensure that the database is configured correctly for your workload. This may involve adjusting various parameters related to caching and memory management.
  Regular Maintenance: Perform regular database maintenance tasks, such as updating statistics and rebuilding indexes, to ensure optimal performance.
  
  Related Information
  
  Monitoring Tools: Use SAP transaction codes like ST02 (Buffer Monitor) and ST04 (Database Performance Monitor) to monitor the performance of the database and the procedure cache.
  SAP Notes: Check for relevant SAP Notes that may provide additional guidance or patches related to performance issues.
  Database Documentation: Refer to the documentation for your specific database (e.g., Oracle, SQL Server, HANA) for best practices on optimizing procedure cache and memory settings.
  
  By addressing the underlying causes and implementing the suggested solutions, you should be able to improve the procedure cache hit ratio and enhance the overall performance of your SAP system.