How To Fix AD646 - Table & (primary key is not compact)

SAP Error Message - Details

• Message type: E = Error

• Message class: AD - Data Dictionary application messages

• Message number: 646

• Message text: Table & (primary key is not compact)

What causes this issue?

The primary key fields in a table must be located together at the
beginning of the table. This condition has not been met in this case,
i.e. there is at least one non-key field between two key fields.

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?

Change the primary key so that all key fields of the table are located
together at the beginning of the table.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message AD646 - Table & (primary key is not compact) ?

  The SAP error message AD646 indicates that a specific database table (denoted by &) has a primary key that is not compact. This typically occurs in the context of database performance and optimization, particularly in SAP systems that use the ABAP Dictionary.
  Cause:
  The primary key of a database table is considered "not compact" when it contains multiple fields that are not optimally structured for storage and retrieval. This can lead to inefficient use of space and slower performance when accessing the table. The compactness of a primary key is important for database indexing and can affect the overall performance of database operations.
  Solution:
  To resolve the AD646 error, you can take the following steps:
  
  
  Analyze the Table Structure:
  
  Review the structure of the table in the ABAP Dictionary (transaction SE11).
  Identify the fields that make up the primary key and assess whether they can be optimized.
  
  
  
  Modify the Primary Key:
  
  If possible, consider reducing the number of fields in the primary key. A compact primary key typically has fewer fields.
  Ensure that the fields in the primary key are of appropriate data types and lengths.
  
  
  
  Use a Surrogate Key:
  
  If the current primary key is too complex, consider introducing a surrogate key (e.g., an integer or UUID) as the primary key and make the original fields a unique index instead.
  
  
  
  Reorganize the Table:
  
  After making changes to the primary key, you may need to reorganize the table. This can be done using transaction SE14 (Database Utility) to adjust the table structure and optimize it.
  
  
  
  Check for Dependencies:
  
  Before making changes, ensure that there are no dependencies or references to the current primary key that could be affected by the change.
  
  
  
  Test Changes:
  
  After making modifications, thoroughly test the changes in a development or quality assurance environment before applying them to production.
  
  
  
  Related Information:
  
  
  Transaction Codes:
  
  SE11: Data Dictionary (to view and modify table structures).
  SE14: Database Utility (to manage database objects).
  
  
  
  Performance Considerations:
  
  Compact primary keys can lead to better performance in terms of data retrieval and storage efficiency.
  Regularly monitor and analyze database performance to identify potential issues related to table structures.
  
  
  
  Documentation:
  
  Refer to SAP documentation and notes for best practices on database design and optimization.
  
  
  
  By following these steps, you should be able to resolve the AD646 error and improve the performance of the affected table in your SAP system.