SAP HANA NSE uses the data volume that the main database is using. While no special configuration steps are necessary for the NSE persistence layer, sizing must consider the additional capacity for the feature.
When you use the SAP HANA NSE feature, a portion of DRAM is used as a buffer cache to dynamically load paged data from the persistence (data volume). By default, the size of this buffer cache is 10 percent of the total main memory of the system. For more information, see “SAP HANA Buffer Cache” in the .
SAP recommends not exceeding a ratio of 1:8 for the total amount of warm data handled by SAP HANA NSE and the buffer cache. When using SAP HANA NSE, you can store data in the warm tier in the following specific granularities:
Data location handling is built into SAP HANA's Data Definition Language (DDL). Manage the configuration by using the SAP HANA CLI SQL client hdbsql or the SQL editor in SAP HANA Studio or SAP HANA Cockpit.
To create a table using SAP HANA NSE (the warm tier), run the following DDL command:
CREATE T_DELL_NSE (id INT, name VARCHAR(100)) PAGE LOADABLE;
To create a specific column in the warm tier, run:
CREATE T_DELL_NSE (id INT PAGE LOADABLE, name VARCHAR(100));
To move an entire existing table to the warm tier, run:
ALTER TABLE T_DELL_NSE PAGE LOADABLE CASCADE
To move a specific column to the warm tier, run:
ALTER TABLET_DELL_NSE ALTER (name VARCHAR(100) PAGE LOADABLE);
, which is based on real-time statistics from an existing SAP HANA database, provides recommendations for which data to move from the hot (in-memory) tier to the warm tier (SAP HANA NSE). Use the SAP HANA NSE Advisor information for guidance regarding the amount of data to move to the warm tier on an existing system.