## 3.7.3  Failed Delta Merge
If many cases are identified where auto merge has failed, the error codes need to be analyzed in more detail. Note that the merge only failed if SUCCESS is not TRUE. In any other case the error code describes a non-critical condition during a successful merge.
To analyze the error codes, you should increase the trace level to INFO for the components mergedog and mergemonitor in the INDEXSERVER section of the Database Trace .
To change the trace configuration choose Trace Configuration from the database context menu in the SAP HANA database explorer and change the configuration of the Database Trace .
The following table lists error codes and typical corrective actions.
## Error Codes
|   Error | Description                                                                                                            | Recommended Action                                                                                                                                                                                             |
|---------|------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|    1999 | General error (no further information available)                                                                       | Check the indexserver trace for more errors regarding the exception                                                                                                                                            |
|    2450 | Error during merge of delta index occurred                                                                             | Check in diagnostic files for an Out-Of-Memory dump that occurred during the delta merge operation                                                                                                             |
|    2458 | Table delta merge aborted as cancel was manually requested by a kill session call.                                     | No action required.                                                                                                                                                                                            |
|    2480 | The table in question is already being merged.                                                                         | No action required.                                                                                                                                                                                            |
|    2481 | There are already other smart merge requests for this table in the queue.                                              | No action required.                                                                                                                                                                                            |
|    2482 | The delta storage is empty or the evaluation of the smart merge cost function indicated that a merge is not necessary. | No further action required if this occurs occasionally. If it happens frequently: Check M_DELTA_MERGE_STATISTICS and review smart merge cost function with SAP experts. (parameter smart_merge_decision_func ) |
|    2483 | Smart merge is not active (parameter smart_merge_enabled=no )                                                                       | Change the parameter smart_merge_enabled=yes )                                                                                                                                                                                                                                                                                                                                                                                                                                              |
|    2484 | Memory required to optimize table exceeds heap limit (for failed compression optimization operations, TYPE=SPARSE, SUCCESS=FALSE ). | No further action required if this occurs occasionally. If it happens frequently: A) Analyze change operations on the table and con- sider table partitioning to minimize the size of the delta storage. If no knowledge about application is available, Hash Partitioning with a size of 500.000.00 records is a good initial choice. B) Analyze change operations on the ta- ble and consider adjusting the parameter auto_merge_decision_func C) Increase delta storage D) Review sizing |
|    6900 | Attribute engine failed                                                                                                             | Internal error. Check the indexserver trace for more errors regarding the exception.                                                                                                                                                                                                                                                                                                                                                                                                        |
|   29020 | ltt::exception caught while operating on $STORA- GEOBJECT$                                                                          | Internal error. Check the indexserver trace for more errors regarding the exception.                                                                                                                                                                                                                                                                                                                                                                                                        |
## Related Information
Memory Information from Logs and Traces [page 66]