What are delta merges in SAP HANA environments?
Changes (INSERT, UPDATE, DELETE) to SAP HANA column store tables are not directly updated in the main storage. Instead, the change information is written to a dedicated delta storage:
From time to time the main storage needs to be updated with the content of the delta storage. This operation is called delta merge. The rough execution steps of a delta merge are illustrated in the following picture:
You can see that during a delta merge two separate main and delta storages exist.