BW on HANA : Memory Used reduction

[Former Member]

Hi HANA Experts,

i run BW on HANA und i have loaded a large amount of data on BW Cubes. The Database Memory Used, as it was shown in Administration from HANA Studio, was up to 192 GB und today it was sundelly dropt to 27 GB without any further operations. I have checked the data in BW and nothing is missing, nobody deleted or compressed any cube, thus i cannot find any explanation.

Has someone faced something like this or have an explanation about it.

Thank you in advanced

Vjola

[former_member184768]

Hi Vjola,

Can you please check the objects which are loaded in the main memory from M_CS_TABLES / M_RS_TABLES.

The memory reduction can happen when the objects are merged / moved out of main memory.

The memory management is handled internally by HANA. Once you start querying the objects by selecting the data, you can see the increase in the memory utilization.

Regards,

Ravi

[Former Member]

Hi Ravi,

tables of _SYS_STATISTICS schema( like: HOST_DELTA_MERGE_STATISTICS, HOST_VOLUME_IO_PERFORMANCE_STATISTICS etc.)

are loaded fully with LAST_MERGE_TIME =06.09.2012

From which column exactly can i see if the data are move out of the main memory or not?

Regards,

Vjola

[former_member184768]

Hi Vjola,

Please look into memory_size_in_total, memory_size_in_main and memory_size_in_delta in M_CS_TABLES.

It will show you how much is in main memory, how much is in Delta (after data load and before merge).

Regards,

Ravi