SAP HANA Native Storage Extension (NSE) is a general-purpose, built-in warm data store in SAP HANA that lets you manage less-frequently accessed data without fully loading it into memory. NSE integrates flash-drive based database technology with the SAP HANA in-memory database for an improved price-performance ratio.
Note: NSE is subject to certain functional restrictions. For more information, see SAP Note 2771956: SAP HANA NSE Functional Restrictions with HANA 2.0 SPS 04 and SAP Note 2927591: (access requires an SAP username and password).
The following figure shows the difference between standard SAP HANA in-memory storage and the storage offered with NSE:
The capacity of a standard SAP HANA database is limited by the amount of main memory. Using SAP HANA NSE, customers can bypass these limits by storing warm data on PowerStore storage. Paging operations require a relatively small amount of SAP HANA memory for the NSE buffer cache because the buffer cache can handle up to eight times the size of warm data on disk. For example, a 2 TB SAP HANA system without NSE equates to a 1 TB database in memory. With NSE and the addition of a 500 GB buffer cache, you can expand your 1 TB database to a 5 TB database consisting of 1 TB of hot data, 4 TB of warm data, and a 500 GB buffer cache to page data between memory and disk. The default buffer cache is set to 10 percent of SAP HANA memory.
While hot data is ‘column loadable’, residing completely in-memory for fast processing and loaded from disk into SAP HANA memory in columns, with SAP HANA NSE you can specify certain warm data as ‘page loadable.’ This data is loaded into memory page by page as required for query processing. Unlike column-loadable data, page-loadable data does not need to reside completely in memory.
The following figure depicts the SAP HANA database with NSE:
NSE reduces the memory footprint for page-loadable data. The database is partly in memory and partly on disk, as illustrated in Figure 9. The PowerStore storage system together with SAP HANA NSE can be used to substantially increase SAP HANA data capacity and reduce TCO for customers.
NSE is integrated with other SAP HANA functional layers, such as the query optimizer, query execution engine, column store, and persistence layers. For more information about SAP HANA NSE and related topics, see SAP HANA Native Storage Extension Whitepaper.