sap bw on hana sizing v1 2

7/21/2019 Sap Bw on Hana Sizing v1 2

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SAP & SAP Customer Internal

SAP BW on HANA (Orange)

Sizing GuidelineVersion 1.2 – March 2012

SAP & SAP Customer Internal



© 2011 SAP AG. All rights reserved. 2SAP & SAP Customer Internal

DISCLAIMER

Sizing recommendations apply for certified hardware only. Please contact

hardware vendor for suitable hardware configuration.

Note that HANA is constantly being optimized. This might have impact on

sizing recommendations, which will be reflected in this document. Therefore,

check for the latest version of this document and the note.

Note that the sizing guideline in this document refers to SAP BW on HANA

(aka Orange) only. Additional applications running on top of HANA are notcovered in this document. Please refer to application specific sizing

guidelines for details in that case.




SAP BW on HANA Sizing Elements

SAP BW on HANA sizing consists of

Memory sizing for column store data

Memory sizing for row store data

Memory sizing for objects created during runtime

(data load and query execution)

Disk Sizing

CPU Sizing




SAP BW on HANA Sizing: Summary

1. RAM

2. Disk

3. CPU

RAM = (Source data footprint –

50GB) * 2 / 4 + 90 GB or

RAM = (colstore tables footprint) * 2 / 4 +

rowstore tables footprint / 1.5 + 50 GB

CPU: to be done

DISKlog = 1 * RAM

DISKpersistence = 4 * RAM




Memory Sizing: Column Store Data

• Memory requirements for column store data is derived from the database footprintof the corresponding tabes of the source database system

• The overall database footprint in source system must be determined using

database specific catalog information (e.g. in Oracle: dba_segments; in DB2:

syscat.tables).

• It is assumed that part of database tables will be stored in row store (all tables that

are NOT generated by BW). In cleansed BW system this is usually about 60 GB

worth of data. However, with large customer data tables, this size can grow

significantly. Note 1637145 contains a script that identifies row store and column

store tables and their cumulated sizes.

• Average compression factor database table size : column store size = 4 : 1

• Note that this compression factor refers to uncompressed database tables, and

space for database indexes is to be excluded.




Memory Sizing: Row Store Data and Caches

• A cleansed BW system usually has about 60 GB of database tables that will be

stored in row store (data dictionary, housekeeping tables, etc.).

• Average compression factor database table size : row store size = 1.5 : 1

A fixed amount of 40 GB for row store data for BW is assumed.

• HANA uses additional caches to accelerate I/O to persistence layer and for other

purposes. These caches can grow but will shrink if memory is needed to store

data. However, a minimum amount of cache memory of 40 GB has been

identified.

• Additional HANA components (statistics server, name server) require 10 GB of

memory.

• Sum of memory not covered by column store: 90 GB


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Memory Sizing: Runtime Objects

Additional memory required for objects that are created dynamically

when loading new data

when executing queries

We recommend to reserve as much memory for dynamic objects as for static

objects in column store:

So the total RAM is

RAMdynamic = RAMstatic

RAM = (Source data footprint – 50GB) * 2 / 4 + 90 GB or

RAM = (colstore tables footprint) * 2 / 4 +

rowstore tables footprint / 1.5 + 50 GB



Disk Sizing

Disk size for persistence layer:

This space does not cover requirements for backup.

Disk size for log files / operational disk space:

DISKlog = 1 * RAM

DISKpersistence = 4 * RAM



Disk Sizing - Details

Disk space is required to persistenly store data that is kept in memory.

The space to be provided must be capable to hold:

• Data in before- and after-image versions (2x)

• Space for at least one process image in case of software failure (1x)

• Space for one data export (1x)

The latter two components are essential to provide support. So a total of 4x

the size of the data in memory is required on disk.

Note that any backup data must NOT be stored in this space, but should

rather be moved to external storage media.



CPU Sizing

Maximize query throughput by multiuser scenarios with queries of different

complexity out of delivered content, 10-20 M records

Assumptions:

- three different query complexity classes

- three different user profiles (click rate, query complexity)- same distribution of user classes and query complexities as in BW

Normalization to query throughput per core resp. active user per core

CPU: to be done



Example

Extract from sizing script output:

Fill Table HANA_ROWSTORE ...

Fill Table HANA_COLSTORE ...

Get Total Sizes for RowStore and ColumnStore Tables (without Aggregates) ...

-----------------------------------------------------------------------------------------

-- Relevant Sizing Information

-- HINT: Aggregates were removed while calculating Size for ColumnStore

-----------------------------------------------------------------------------------------

RowStore Tables [GB] ColumnStore Tables [GB] Total Size [GB]

-------------------- ----------------------- ---------------

49.56 672.35 701.91

Table footprint of source database: 50 GB row store + 672 GB column store

RAM = (colstore tables footprint) * 2 / 4 +rowstore tables footprint / 1.5 + 50 GB

= 672 GB * 2 / 4 + 50 GB / 1.5 + 50 GB = 419 GB

Diskpersistence = 419 GB * 4 = 1676 GB

Disklog = 419 GB

sap bw on hana sizing v1 2

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