HANA Sizing - How to reduce the size further?

[abhishek_shanbhogue2]

Hi All

We are upgrading our BW system from from 3X to latest 7X and migrating to HANA. Our system size is 2.5TB and we have Stats Cube, Change Logs and PSA tables which are accounting to 1TB. After our housekeeping activities we have reduced the size of our DB to 1.3TB and when we run the HANA sizing report we dont see any impact on the output before and after our housekeeping activities

After we reduced out DB the largest tables that we see are the RSD* tables (ROW Based) and Fact, Active Tables and Change Logs (COL). Should we reduce the Row based tables instead of Col? should we ignore RSD* tables for sizing?

Memory Requirement (Minimum Total): 780GB (Before) 777GB (After)

HANA Sizing Report which was used  - /SDF/HANA_BW_SIZING

Selections: Supress tables < 1MB - X, One Table Per RFC - X, Precision - High, Non Active Data - X

PS: We were aiming for 512GB Hardware but it looks like we need more than what we anticipated

Largest Tables

RSZWOBJ

RSBATCHDATA           

RSR_CACHE_DB_IX       

REPOLOAD               

RSDDSTATEVDATA         

RSMONMESS              

REPOSRC                

EDIDS                  

Thanks

Abhishek Shanbhogue

[roland_szajko]

Hi Abhishek

RSBATCHDATA -  can be cleaned via transaction RSBATCH (https://help.sap.com/saphelp_nw73/helpdata/en/48/d2a551003c04e9e10000000a42189c/frameset.htm)

RSDDSTATEVDATA - as far i remember this is cleaned up with program RSDDSTAT_DATA_DELETE

RSMONMESS - archive BW request administration data via BWREQARCH (Archiving Request Administration Data - Data Warehouse Management - SAP Library)

EDIDS - Note 1675286

br

Roland

[desgallagher]

Hi Abhishek,

I am surprised the you clean the system from 2.5 to 1.3 TB and you see little impact on the BW on HANA Sizing report. It is important that the database statistics are up to date before you run the report for all tables. Can you please check that you are using the latest version of the BW on HANA Sizing report from the note  1736976 - Sizing Report for BW on HANA?

To reduce the overall size of the system it is important to make both Row and column store tables as small as possible. It can be the case that that the row store size has a significant impact on the system as you tend to get less compression with row store compare to column store tables.

Kind Regards,

Des

[abhishek_shanbhogue2]

Hello Des Gallagher,

We were not referring the latest version of the sizing report and we also figured out a bug which was ignoring a change log table having more than 2 billion records. After cleaning of the CL table we could see the sizing program worked.

Thanks

Abhishek Shanbhogue

[Former Member]

HI,

Please archive historical data to other database like sy-base IQ and check whether you can achieve expected 512GB size of HD.

check this link for more details.

Regards,

Antony Jerald.

[abhishek_shanbhogue2]

Thanks Antony for your response. Archiving is one option which cannot go with considering the project deadline

[Former Member]

Were you guys good with 512GB?

We are in similar situation. I believe when HANA report sizes the system; it considers full size of all column storage tables. Considering the fact that , we have multiple layers of data in traditional database schema, we might not need to duplicate the data and we won't be bringing everything in memory together (We would use unload programs after data is loaded in one data flow etc); we are considering to go with 512GB even if it is slightly higher in the report.

Give your opinion please!

[abhishek_shanbhogue2]

Hello S Kaur,

After further reduction of certain standard tables and business content we were able to achieve 512GB, but things become tighter after go live and you will need to chalk out a detailed housekeeping plan/policy so that the memory consumption is not above the RED mark.

Thanks

Abhishek Shanbhogue