Error
Error Code:
1345
SAP S/4HANA Error 1345: SQLScript Concurrent Write Restriction
Description
This error, ERR_SQLSCRIPT_NOT_ALLOWED_CONCURRENT_WRITES, indicates that an SAP HANA SQLScript procedure or function is attempting to perform multiple write operations on the same data concurrently. This restriction is in place to maintain data integrity and consistency within the database. It typically occurs in scenarios involving complex SQLScript logic that tries to modify shared data simultaneously within a single execution context or across implicitly parallel processes.
Error Message
ERR_SQLSCRIPT_NOT_ALLOWED_CONCURRENT_WRITES: Not allowed concurrent write
Known Causes
3 known causesMultiple Updates in Single Transaction
A SQLScript procedure attempts to modify the same database table or data set multiple times within a single transaction using different sub-operations without proper sequencing.
Parallel Write Operations
The SQLScript logic is designed to perform write operations in parallel on the same target data, which SAP HANA's SQLScript engine restricts to prevent data corruption.
Incorrect Data Modification Pattern
The SQLScript code violates allowed data modification patterns, such as trying to update a table that is also being read or updated by another part of the same complex statement.
Solutions
3 solutions available1. Analyze and Optimize Concurrent SQLScript Execution advanced
Identify and refactor SQLScripts causing concurrent write conflicts.
1
Identify the specific SQLScript that is triggering the concurrent write error. This often involves reviewing application logs, tracing tools (like SAP's ST05 or SAT), and potentially the database trace if the error originates from a stored procedure or function.
2
Examine the SQLScript code for operations that modify the same data concurrently. This could include INSERT, UPDATE, DELETE statements on shared tables, or modifications within loops without proper synchronization mechanisms.
3
If the SQLScript is part of a custom application, consider refactoring the logic to serialize write operations or to use optimistic locking mechanisms. For standard SAP S/4HANA processes, this usually requires SAP Notes or specific configuration changes.
4
Implement appropriate locking mechanisms within the SQLScript if absolutely necessary, but be aware this can impact performance. Consider using row-level locking or table locks judiciously, and ensure they are released promptly. Example (conceptual, actual implementation depends on context):
/* Conceptual example: Lock a specific row before update */
LOCK TABLE my_table IN ROW EXCLUSIVE MODE;
UPDATE my_table SET column = 'new_value' WHERE id = 123;
COMMIT;
/* Release lock implicitly with COMMIT or ROLLBACK */5
If the concurrent writes are unavoidable and part of a legitimate business process, investigate SAP Notes related to the specific transaction or module that is failing. SAP might provide patches or configuration guidance.
2. Review and Adjust Transaction Isolation Levels medium
Temporarily or permanently alter transaction isolation levels to mitigate concurrency issues.
1
Understand the current transaction isolation level of the affected sessions. This can often be checked using database-specific SQL commands.
SELECT PROPERTY, VALUE FROM SYS.GLOBAL_PROPERTIES WHERE PROPERTY = 'transaction_isolation_level';2
For a quick test or in environments where data consistency can be slightly relaxed for certain operations, consider temporarily setting a less restrictive isolation level (e.g., READ COMMITTED) for the specific user or session that is encountering the error. This should be done with extreme caution and thorough testing.
SET TRANSACTION ISOLATION LEVEL READ COMMITTED;3
If the error persists or a more permanent solution is needed, analyze the impact of changing the default transaction isolation level for the entire database or specific schemas. Consult with your SAP functional team and SAP Basis team to understand the implications for data integrity and other business processes before making permanent changes.
4
The ideal scenario is to fix the underlying SQLScript logic rather than relying solely on isolation level changes. Isolation level adjustments are often a workaround, not a root cause solution.
3. Leverage SAP Notes and Support for Known Issues easy
Apply SAP Notes or engage SAP support for documented bugs or performance issues.
1
Search the SAP Support Portal (SAP ONE Support Launchpad) for SAP Notes related to 'ERR_SQLSCRIPT_NOT_ALLOWED_CONCURRENT_WRITES', 'SQLScript concurrent write', or the specific transaction code or application area where the error occurs.
2
If a relevant SAP Note is found, carefully review its description, prerequisites, and implementation steps. Apply the note following standard SAP transport procedures.
3
If no relevant SAP Note is found, and the issue is reproducible, consider opening an incident with SAP Support. Provide detailed information about the error, the steps to reproduce it, the affected system components, and any troubleshooting steps already taken.