Hi,
We are running HANA database (102.05) with almost half TB RAM and around 29GB of column store tables and 19MB of Row Store tables in our dev environment.
I frequently observed that the HANA Used Memory is not being released after completion of the query whenever any bad query/statement/Calculation view is executed. To further analyze the issue I have ran many reports and looked at different sources and that investigation led me into lot many other questions.
On the HANA Studio overview screen I can see that the used memory is at around 127 GB and the other report showed the memory usage breakup with the component "Statement Execution & Intermediate Results" taking the top spot with around 70 GB memory consumption and then the Column Store Tables at 53GB (But the actual Column store is only 29GB).
Image1: Screenshot from Studio - HANA Used Memory is 127 GB approx

Image2: Result screenshot of the Component wise memory usage for Index Server (Port 30003)

Image3: Column Store table size

Image4: Row Store table size

On the other hand the below query shows me that the total Memory consumption by HANA is at 134 GB but the studio overview shows only 127 GB (Imange1)
Image5: Total HANA Memory usage

Image6: Memory usage by individual Services

After looking at all these sources with different results, I have got below questions/doubts
1) Is the component "Statement Execution & Intermediate Results" (Image) the culprit for HANA Used memory not being released? Is this a bug or do I have to tune any parameter or run query to release the Used Memory?
2) Why is there difference between the Column Store (Image3) and Row Store (Image4) tables sizes shown with the individual queries and the result shown in the Component wise memory usage report ( Image2)
3) Why is there a difference between the HANA Used memory shown on studio (Image1) and the result obtained from the query (Image5)
4) Image 6 shows few services have Used Memory higher than Resident Memory. Is this possible? My understanding was that the Used memory and Resident memory could be equal or Resident memory could be higher than the Used Memory but looks like I am missing something.
5) In ABAP stack systems we have a parameter to let the work process to restart after it consumes certain amount of heap memory but I am not sure if any such parameter available in HANA to release the memory after memory usage reaches certain limit per query/statement or the whole database. I am sure HANA has its own memory management mechanism without the need for such parameters but just asking..
Regards,
Ashok Oleti