How To Fix SMMSS_DDIC004 - There can be only one clustered index

SAP Error Message - Details

• Message type: E = Error

• Message class: SMMSS_DDIC - DDIC Messages for Microsoft SQL Server

• Message number: 004

• Message text: There can be only one clustered index

What causes this issue?

You have set CLUSTERED YES for an index. However, there is already a
clustered index in the database.

System Response

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

How to fix this error?

If you want this index to be clustered, you must set the currently
clustered index to CLUSTERED NO.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message SMMSS_DDIC004 - There can be only one clustered index ?

  The SAP error message SMMSS_DDIC004 indicates that there is an attempt to create more than one clustered index on a database table. In relational database management systems (RDBMS), a clustered index determines the physical order of data in a table and there can only be one clustered index per table.
  Cause:
  The error typically arises in the following scenarios:
  
  Multiple Clustered Index Definitions: When trying to define a second clustered index on a table that already has one.
  Table Redefinition: If a table is being redefined or modified in a way that inadvertently attempts to create a second clustered index.
  Database Migration or Upgrade: During a migration or upgrade process, the system might attempt to create indexes that conflict with existing ones.
  
  Solution:
  To resolve the error, you can take the following steps:
  
  
  Check Existing Indexes:
  
  Use the database management tools or SQL queries to check the existing indexes on the table. Ensure that there is only one clustered index defined.
  
  
  
  Modify Index Creation:
  
  If you are trying to create a new clustered index, you will need to drop the existing clustered index first. This can usually be done with a command like:
  DROP INDEX index_name ON table_name;
  
  After dropping the existing clustered index, you can create the new one:
  CREATE CLUSTERED INDEX new_index_name ON table_name (column_name);
  
  
  
  
  Review Table Design:
  
  If you are designing a new table or modifying an existing one, ensure that you only define one clustered index in your table definition.
  
  
  
  Consult Documentation:
  
  Refer to the SAP documentation or the specific database documentation (e.g., HANA, Oracle, SQL Server) for guidelines on index creation and management.
  
  
  
  Check for System Issues:
  
  If this error occurs unexpectedly, check for any system issues or bugs that might be causing the problem. Sometimes, a system update or patch may be required.
  
  
  
  Related Information:
  
  Clustered Index: A clustered index sorts and stores the data rows in the table based on the key values. It is important for performance optimization in queries.
  Non-Clustered Index: Unlike a clustered index, a non-clustered index does not affect the physical order of the data in the table and can be created multiple times.
  Database Management: Understanding how your specific database management system handles indexes is crucial, as different systems may have different rules and capabilities.
  
  If you continue to experience issues after following these steps, consider reaching out to your database administrator or SAP support for further assistance.