About
Resident memory in Hana.
See also: SAP Hana - Memory
Once a temporary computation completes or a table is dropped, the freed memory is returned to the memory manager, who recycles it to its pool, usually without informing the OS. Thus, from SAP HANA’s perspective, the amount of Used Memory shrinks, but the process’ virtual and resident sizes are not affected.
Articles Related
Monitoring
Hana Studio
Database Resident
For the SAP Hana process:
SELECT
round(SUM(PHYSICAL_MEMORY_SIZE)/1024/1024/1024,2) as "Database Resident Memory (Gb)"
FROM
M_SERVICE_MEMORY
Example:
1,75
Total Resident (Host Resource Utilization)
SELECT
T1.HOST
, ROUND(( T1.USED_PHYSICAL_MEMORY + T2.SHARED_MEMORY_ALLOCATED_SIZE ) / 1024 / 1024 / 1024, 2 ) AS "Host Memory (Gb)"
FROM
M_HOST_RESOURCE_UTILIZATION AS T1
JOIN
(
SELECT
M_SERVICE_MEMORY.HOST
, SUM( M_SERVICE_MEMORY.SHARED_MEMORY_ALLOCATED_SIZE ) AS SHARED_MEMORY_ALLOCATED_SIZE
FROM
SYS.M_SERVICE_MEMORY
GROUP BY
M_SERVICE_MEMORY.HOST
) AS T2
ON
T2.HOST = T1.HOST;
1,5
Others
select
HOST,
round((USED_PHYSICAL_MEMORY + FREE_PHYSICAL_MEMORY)/1024/1024/1024, 2) as "Physical Memory GB",
round(USED_PHYSICAL_MEMORY/1024/1024/1024, 2) as "Resident GB"
from
PUBLIC.M_HOST_RESOURCE_UTILIZATION
Support
Comparison Total Resident vs Database Resident Memory
If the difference between 'Total Resident' and 'Database Resident' is below a significant threshold (2GB), there is no indication that processes outside the database contribute significantly to memory consumption.