Which type of tables required extended storage?

Extended storage is specifically associated with multistore tables in SAP HANA. These tables are designed to handle larger volumes of data by utilizing external storage options beyond the in-memory capabilities of the HANA system. Multistore tables allow for the storage of data that does not need to reside in the high-speed in-memory environment but still requires accessibility for analytics and reporting purposes.

In contrast, in-memory tables, column tables, and row tables primarily reside within the in-memory memory architecture of HANA to leverage its high performance. While column and row tables each have specific use cases regarding how data is structured and accessed, they are fundamentally designed to operate within the confines of HANA's memory capabilities, focusing on speed and efficiency.

Therefore, multistore tables uniquely extend the data storage model of HANA, combining both in-memory processing for critical data and disk-based storage for larger, less frequently accessed datasets, thus justifying the requirement for extended storage.