How To Fix AD338 - Use another data type in the pool key

SAP Error Message - Details

• Message type: E = Error

• Message class: AD - Data Dictionary application messages

• Message number: 338

• Message text: Use another data type in the pool key

What causes this issue?

The key of a pooled table may contain only CHAR-type data types (without
conversion): CHAR, NUMC, ACCP, CLNT, CUKY, DATS, TIMS, LANG,
UNIT.

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?

Use a valid data type or remove the field from the key part.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message AD338 - Use another data type in the pool key ?

  The SAP error message AD338, which states "Use another data type in the pool key," typically occurs in the context of ABAP programming when you are trying to define a key for a pooled table or a cluster table. This error indicates that the data type you are using for the key field is not compatible with the requirements for pooled or cluster tables.
  Cause:
  
  Incompatible Data Type: The key field in a pooled or cluster table must be of a specific data type. Commonly, the key fields should be of type CHAR, NUMC, or DATS. If you are using a different data type (like STRING, FLOAT, etc.), you will encounter this error.
  Key Field Definition: The definition of the key fields in the table may not adhere to the constraints set by SAP for pooled or cluster tables.
  
  Solution:
  
  Change Data Type: Review the data types of the key fields in your pooled or cluster table definition. Change any incompatible data types to one of the acceptable types (e.g., CHAR, NUMC, or DATS).
  Check Table Definition: Ensure that the table definition aligns with SAP's guidelines for pooled and cluster tables. You can refer to the SAP documentation for more details on the requirements.
  Recreate the Table: If necessary, you may need to recreate the table with the correct data types for the key fields.
  
  Related Information:
  
  Pooled Tables: These are special types of tables in SAP that allow multiple logical tables to share the same physical table in the database. They are used to optimize database space.
  Cluster Tables: Similar to pooled tables, cluster tables allow multiple logical tables to be stored together. They are used for storing data that is frequently accessed together.
  Data Dictionary (SE11): You can use transaction SE11 to view and modify the definitions of database tables, including pooled and cluster tables.
  ABAP Development: Familiarity with ABAP programming and data dictionary concepts is essential for resolving this error.
  
  If you continue to face issues after making the necessary changes, consider consulting with a colleague or reaching out to SAP support for further assistance.