How To Fix DB6PM845 - No index has been recommended, no existing index is used

SAP Error Message - Details

• Message type: E = Error

• Message class: DB6PM - DB2 UDB for UNIX, Windows: Performance Monitoring

• Message number: 845

• Message text: No index has been recommended, no existing index is used

Self-Explanatory Message

Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of messages in the SAP system have a message text, however this is frequently insufficient to comprehend or resolve the problem.

To make things easier, more detailed information is frequently added to describe the issue, how to fix it, and the necessary steps or configuration modifications.

Unfortunately, there isn't any extra information in this error notice.

What else can you do?

First, use our AnswerBot below to get a possible cause and solution (requires a premium subscription).

Also, review the in-depth Common Questions & Answers listed below; you could discover a solution there or be able to connect with others who have faced similar challenges.

You can also try searching the SAP support portal (support.sap.com) but you need a special user ID to access it. It is possible that an SAP support note exists that provides additional details about the mistake or even steps for fixing it.

Smart SAP Assistant

• What is the cause and solution for SAP error message DB6PM845 - No index has been recommended, no existing index is used ?

  The SAP error message DB6PM845 indicates that the database optimizer has not recommended any index for a particular SQL statement, and no existing index is being utilized for that query. This can lead to performance issues, as the database may need to perform a full table scan instead of using an index to quickly locate the required data.
  Causes:
  
  Lack of Suitable Indexes: There may not be any indexes defined on the columns being queried, or the existing indexes may not be optimal for the query.
  Query Structure: The SQL query may not be structured in a way that allows the optimizer to utilize existing indexes effectively.
  Statistics: Outdated or missing statistics can lead the optimizer to make poor decisions regarding index usage.
  Database Configuration: Certain database settings or configurations may affect how indexes are used or recommended.
  Data Distribution: The distribution of data in the table may not favor the use of indexes, especially if the queried data is not selective.
  
  Solutions:
  
  
  Create or Modify Indexes:
  
  Analyze the SQL query and determine if additional indexes are needed on the columns being queried.
  Consider creating composite indexes if multiple columns are frequently queried together.
  
  
  
  Update Statistics:
  
  Ensure that the database statistics are up to date. This can often be done using commands like ANALYZE TABLE or similar, depending on the database system in use.
  
  
  
  Rewrite the Query:
  
  Sometimes, rewriting the SQL query can help the optimizer make better use of existing indexes. This may involve changing the order of conditions, using different join types, or simplifying the query.
  
  
  
  Use Query Hints:
  
  In some cases, you can provide hints to the optimizer to encourage it to use a specific index or to consider certain indexes.
  
  
  
  Database Tuning:
  
  Review the database configuration and tuning parameters to ensure they are optimized for performance.
  
  
  
  Monitor and Analyze:
  
  Use database monitoring tools to analyze query performance and identify potential bottlenecks or issues with index usage.
  
  
  
  Related Information:
  
  Database Documentation: Refer to the documentation for your specific database system (e.g., Oracle, SQL Server, etc.) for details on index creation, statistics management, and query optimization.
  SAP Notes: Check SAP Notes and Knowledge Base Articles for any specific recommendations or patches related to this error message.
  Performance Tuning: Consider engaging with a database administrator (DBA) or performance tuning expert if the issue persists, as they can provide deeper insights and recommendations tailored to your specific environment.
  
  By addressing the underlying causes and implementing the suggested solutions, you can improve the performance of your SQL queries and resolve the DB6PM845 error.