Showing posts with label hot-data. Show all posts
Showing posts with label hot-data. Show all posts

Thursday, 26 May 2016

Managing cold data in SAP HANA database memory

So once you have the cold data moved away from the main memory you will notice that it is re-loaded whenever needed. But for how long will the cold data stay in memory so that the aging still makes sense? This blog explains how cold data is managed in memory and describes different strategies for keeping it all under control.

HANA database takes care of loading and unloading data to and from memory automatically with the aim to keep all relevant information in memory. In most cases only the necessary columns (i.e. columns that are actually used) are loaded into memory on the first request and kept there for later use. For example after system restart only a few columns might be initially loaded into memory and only for the hot partition as shown in the figure below.