How To Fix AQ639 - More than 16 tables cannot be processed here

SAP Error Message - Details

• Message type: E = Error

• Message class: AQ - Message texts for SAP Query

• Message number: 639

• Message text: More than 16 tables cannot be processed here

What causes this issue?

You attempted to bring in more than 16 tables into the join definition.
This is currently not possible.

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?

Check whether the combination of this data is not available in fewer
tables.
Take into account the possibility of database views or logical
databases.
Consider, where necessary, the creation of a database view for the
combination of several tables and use of this view in the ABAB Join.

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 AQ639 - More than 16 tables cannot be processed here ?

  The SAP error message AQ639 ("More than 16 tables cannot be processed here") typically occurs when you are trying to perform an operation that involves more than 16 database tables in a single SQL statement or operation. This limitation is often encountered in scenarios involving joins, subqueries, or when using certain SAP functions that have a restriction on the number of tables that can be processed simultaneously.
  Cause:
  
  SQL Statement Limitation: The error arises because the SQL statement or operation you are trying to execute involves more than 16 tables. This is a limitation in the database or the way SAP handles SQL operations.
  Complex Queries: If you are executing a complex query that joins multiple tables, it may exceed the limit.
  Function Module or Report: Certain function modules or reports may have internal limitations on the number of tables they can handle.
  
  Solution:
  
  Simplify the Query: Try to break down the query into smaller parts. Instead of joining all tables in one query, consider executing multiple queries and then combining the results in your application logic.
  Use Views: If applicable, create database views that encapsulate the logic of multiple tables. This way, you can reduce the number of tables being processed in a single operation.
  Check Function Modules: If you are using a specific function module, check its documentation to see if there are alternative ways to achieve your goal with fewer tables.
  Optimize Data Retrieval: Review the data retrieval logic to see if all tables are necessary for the operation. Sometimes, not all data is needed for the final output.
  Consult SAP Notes: Check the SAP Support Portal for any relevant notes or updates that might address this limitation or provide alternative solutions.
  
  Related Information:
  
  Database Limitations: Different databases may have different limitations regarding the number of tables that can be joined in a single query. It's essential to be aware of the specific database you are using with SAP.
  Performance Considerations: Even if you can technically join more than 16 tables, doing so may lead to performance issues. Always consider the performance implications of complex queries.
  SAP Community: Engaging with the SAP Community or forums can provide insights from other users who may have encountered and resolved similar issues.
  
  If the problem persists after trying the above solutions, it may be beneficial to consult with your SAP Basis or ABAP team for further assistance.