Monitoring and Troubleshooting Merge for Data and Delta File Pairs
Applies To: SQL Server 2016
In-Memory OLTP uses a merge policy to merge adjacent data and delta file pairs automatically. You cannot disable merge activity.
You can monitor data and delta file pairs, as follows:
Compare the size of in-memory storage to overall size of storage. If the storage is dis-proportionately large, then it is likely that merge is not getting triggered. For information
Look at the used space in data and delta files using sys.dm_db_xtp_checkpoint_files (Transact-SQL) to see if merge is not getting triggered when it should.