How To Fix DMC_RT_MSG235 - Secondary index contains duplicate values

DMC_RT_MSG235 - Overview

• Message type: E = Error

• Message class: DMC_RT_MSG - DMC: Runtime Object Messages

• Message number: 235

• Message text: Secondary index contains duplicate values

What causes this issue?

The system cannot either insert a record or update a record in the
target system table, as this would violate a unique secondary index for
the table.

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

System Response

The system stops the transfer of records to the target system.

How to fix this error?

By default, to improve performance, the system first reads the entries
from the logging tables in the order of the key fields of the source
table, then reads the entries in the order of the key field of the
logging table (field IUUC_SEQUENCE). This means that the order in which
changes occur in the source system is not considered, which could result
in a potential conflict for the secondary index in the target system. To
preserve the order of the changes in the source system, you can
configure SAP LT Replication Server such that the entries are only read
from the logging table in the order of field IUUC_SEQUENCE.
Two options are possible:
Remove the unique secondary index from the target table<(>,<)> or change
it to a non-unique secondary index. If necessary<(>,<)> reset the status
of the table in the central system. The central system will start
replicating data from the source system table to the target system table
again.
If you want to keep the unique secondary index in the target system<(>
,<)> set the field READ_SEQU_ORDER in table IUUC_PERF_OPTION to ?X? and
reload the table. The SAP LT Replication Server system will read the
entries from the logging table in the order of the key field of the
logging table (field IUUC_SEQUENCE), therefore preserving the order of
the changes in the source system. However, performance is not optimized.
Note that you cannot use the option <ZK>Use Key Fields to Calculate
Ranges</> in transaction LTRS.

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 DMC_RT_MSG235 - Secondary index contains duplicate values ?

  The SAP error message DMC_RT_MSG235 indicates that there are duplicate values in a secondary index, which can lead to issues in data processing, especially in scenarios involving data migration or replication. This error typically arises in the context of SAP Data Migration Cockpit (DMC) or when working with data models that rely on unique constraints.
  
  Cause:
  The primary cause of this error is the presence of duplicate entries in the fields that are defined as part of the secondary index. This can happen due to:
  
  Data Quality Issues: The source data may contain duplicates that violate the uniqueness requirement of the secondary index.
  Incorrect Data Mapping: During data migration, if the mapping of fields is not done correctly, it can lead to duplicates being created.
  Concurrency Issues: If multiple processes are inserting or updating records simultaneously, it may lead to duplicates being created in the secondary index.
  
  
  Solution:
  To resolve the DMC_RT_MSG235 error, you can follow these