As of SAP HANA SPS 09 the memory footprint of the Paged Attributes is enhanced. It is possible to configure the amount of memory used by page loadable columns.
- The parameter for the lower limit is page_loadable_columns_min_size (page_loadable_columns_min_size_rel) which is set to 5% of the effective allocation limit of the indexserver per default.
- The parameter for the upper limit is page_loadable_columns_limit (page_loadable_columns_limit_rel) which is set to 10% of the effective allocation limit of the indexserver per default.
The memory consumption used by page loadable columns can fluctuate between the two limits. If the upper limit is exceeded, all page loadable columns objects are unloaded until the lower limit is reached again. The default values are quite high. Nevertheless the lower limit should be set to > 0, otherwise performance issues might occur. Still, pages are reported in the memory statistics as part of “Used Memory”. The memory consumed by pages has to be measured separately. This has to be considered when reporting memory statistics.
If an inverted index is defined on a page loadable column an gradual increase of the allocated paged memory might happen and even exceed the limits defined by the parameters above. (SAP Note 2497016).