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SAP HANA Native Storage Extension (NSE) is a general-purpose, onboard 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-to-performance ratio. Using SAP HANA NSE enables the customer to achieve dramatic savings in SAP licensing costs.
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: SAP HANA NSE Functional Restrictions with HANA 2.0 SPS 05 (access to these notes requires SAP login credentials).
The following figure shows the difference between standard SAP HANA in-memory storage and the storage that is 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 a PowerStore system. 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 amount 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,’ which means it resides in-memory for fast processing and is loaded from disk into memory in columns, you can specify certain warm data as ‘page loadable’ with SAP HANA NSE. This data is loaded into memory page by page as required for query processing. Unlike column-loadable data, page-loadable data need not 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 8. The PowerStore storage system together with SAP HANA NSE can 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, see SAP HANA Native Storage Extension.