How To Fix RSCV525 - ORACLE: Index &1 has possibly degenerated

SAP Error Message - Details

• Message type: E = Error

• Message class: RSCV - Analysis of BW objects (InfoCubes...)

• Message number: 525

• Message text: ORACLE: Index &1 has possibly degenerated

What causes this issue?

Index &v1& is <ZK>possibly</> corrupt. It contains &v2& blocks, whereas
table &v3& contains only &v4&. This could indicate that the index is
corrupt, but is not proof that this is actually the case.
<ZH>Background:</> There is no exact method of identifyiong a corrupt
index. The only way to tell if an index has been corrupted is, for
example, to delete the index and reconstruct it, paying attention as
you do so to how the memory usage changes during the process.

System Response

Using this index to access the system, is no longer efficient and leads
to impaired performance. The index needs to be reconstructed.

How to fix this error?

The index must be repaired. Use a repair routine that has been assigned
to this analysis routine (function <PF>Remove Errors
</> in transaction <ZH>RSRV</>).
Alternatively, you can delete and reconstruct the index manually by
using the ABAP data dictionary.
If after you have repaired the index &v1&, the system still tells you
that the index is <ZK>possibly corrupt</>, then there has been a
mistake in the way the index has been assessed. The index is not really
corrupt at all, and you can ignore the warning message in this case.

Procedure for System Administrators

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

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message RSCV525 - ORACLE: Index &1 has possibly degenerated ?

  The SAP error message RSCV525, which states "ORACLE: Index &1 has possibly degenerated," typically indicates that an index in the Oracle database has become inefficient or fragmented, leading to performance issues when accessing the associated table. This can happen due to various reasons, such as frequent updates, deletes, or inserts on the indexed table, which can lead to a situation where the index no longer provides optimal performance.
  Cause:
  
  Fragmentation: Over time, as data is modified, the index can become fragmented, leading to inefficient access paths.
  Data Changes: Frequent changes to the underlying data (inserts, updates, deletes) can cause the index to become less effective.
  Statistics: Outdated or missing statistics can lead the Oracle optimizer to make poor decisions regarding index usage.
  Index Structure: The structure of the index may not be optimal for the current data distribution.
  
  Solution:
  
  
  Rebuild the Index: The most common solution is to rebuild the index. This can be done using the following SQL command:
  ALTER INDEX index_name REBUILD;
  Replace index_name with the actual name of the index mentioned in the error message.
  
  
  Gather Statistics: After rebuilding the index, it is also a good practice to gather statistics on the table and the index to ensure the Oracle optimizer has the most up-to-date information:
  EXEC DBMS_STATS.GATHER_TABLE_STATS('schema_name', 'table_name');
  Replace schema_name and table_name with the appropriate values.
  
  
  Monitor Index Usage: Use Oracle's tools to monitor index usage and performance. This can help identify if the index is still needed or if it can be dropped.
  
  
  Consider Indexing Strategy: Review the indexing strategy for the table. It may be beneficial to create new indexes or modify existing ones based on the current data access patterns.
  
  
  Database Maintenance: Regularly perform database maintenance tasks, such as index rebuilding and statistics gathering, to prevent similar issues in the future.
  
  
  Related Information:
  
  Oracle Documentation: Refer to Oracle's documentation for more details on index management and performance tuning.
  SAP Notes: Check SAP Notes for any specific recommendations or patches related to this error message.
  Performance Monitoring Tools: Utilize Oracle's performance monitoring tools (like AWR reports) to analyze the performance of queries and indexes.
  
  If the problem persists after taking these actions, it may be necessary to consult with a database administrator or SAP support for further investigation.