Performance Improvement in ECC - Leverage Power of HANA

System is slow is one of the common complaints from users of SAP ECC. Root cause analysis

of the scenario may lead to some reasons - Poor performance, huge data volumes, Speed of

Analysis and Reporting etc. In these Challenging times, access to trusted, timely, accurate and

detailed information in certain important Business areas could make the difference between

corporate success or failure.

SAP HANA gives businesses the ability to perform complex calculations faster than ever in real

time. Its capabilities like In-memory computing, Columnar Storage etc can be leveraged to

process large data volumes in a more efficient way, which in turn will help address ERP

performance issues to a great extent.

HANA Innovations

Among various HANA innovations from SAP that are currently available for use for Customers

(as of Nov 2012) , SAP HANA accelerators(CO-PA being the most famous one) and using

HANA as a Secondary database for existing ERP are the best fit to improve performance. With

most of the business logic in ECC being heavily done in ABAP layer, customers will not see any

huge benefit buying HANA as a database. SAP cannot rewrite everything in ECC to work on

HANA. This means that we can expect more accelerators to be built by SAP, and more specialty

applications for ECC that needs HANA. Some of the HANA scenarios that are currently available

are shown below:

1. SAP HANA Accelerators:

These are standard accelerators provided by SAP. Primary data storage stays in ERP and HANA

is used as a secondary database. How to use HANA as a secondary database connection is well

explained in Thomas Jungs blog HANA Connectivity via Secondary database connection.

Data is replicated from ERP to HANA through SAP LT replication server. These accelerators

further read data from SAP HANA database instead of classical database, help in enjoy ing

significant acceleration and hence can reap the benefits of HANA.

Some of the SAP accelerators that are currently available are :

CO-PA - Profitability Analysis Accelerator

FI - Financial Accounting Accelerator

CO - Controlling Accelerator

Material Ledger Accelerator

Each of these accelerators have a set of Technical Pre-requisites - like HANA box and ERP EHP

(ERP 6.0, EHP 6), Netweaver EHP, SP and for SAP Kernel etc. These accelerators are built using

non-disruptive model (Plug-and-play) and can be readily used (Deployment is possible with

very little customizing, within few weeks). Benchmarking figures gathered from Use cases of

standard reports powered by these accelerators have shown an acceleration factor of around 40 to

50 which is a very good indicator of performance improvement.

2. SAP HANA as Secondary Database to accelerate ECC Transactions/reports

Performance of Custom/standard reports/transactions can be improved by using the same

approach of accelerators. In this scenario, HANA is used as secondary database and data is

replicated to HANA d/b from ERP. Transaction/Report needs to be slightly modified to read data

from HANA d/b instead of the classical database. Technical Pre-requisite in this scenario would

be to have a HANA box and ERP EHP (ERP 6.0, EHP 6), Netweaver EHP, SP and for SAP

Kernel etc.

How can I detect Optimizing potential for HANA? , How can I optimize my existing code ,

How can I fully exploit the power of SAP HANA?, could be some of the questions lingering in

the minds of the Application developer to improve performance. Some of the optimization

techniques that can be used here are explained as follows:

Use power of Open SQL replace classic ABAP coding by advanced Open SQL features like

- Joins, Sub-selects, Sorting, Aggregations, etc can be used.

- Database round trips and transferring data too much data into application server needs to be

reduced.

- Parallelization on SAP HANA can be benefited implicitly.

- Avoid Native SQL and prefer Open SQL due to the reasons that we already know Open

SQL is integrated in ABAP language and development infrastructure and it works on all

databases.

Open SQL Guidelines general performance guidelines like the following stay valid:

- Keep the result set small SELECT from instead of SELECT * from

. This is very important with SAP HANA as not only the data transferred matters,

but also the number of columns to be accessed by the database

- Minimize the amount of data transferred use aggregate functions together with group by,

having SELECT carrid connid fldate MAX( luggweight ) INTO (ls_sbook-carrid,

ls_sbook-connid...) FROM sbook GROUP BY carrid connid fldate HAVING MAX(

luggweight ) > 20. Observations have shown that SELECT COUNT(*) can be much faster on

SAP HANA (especially when using non-key fields) , aggregate functions can be performed

very efficiently by SAP HANA, transferring calculations (including sorting / grouping) to the

SAP HANA database can increase overall performance. This means Aggregations including

sorting and grouping is a big strength of SAP HANA.

- Minimize the number of data transfers - e.g. avoid nested SELECT ENDSELECT loops.

Using array fetches (instead of record by record transfer) is also important for SAP HANA.

- Minimize the search overhead - e.g. specify the WHERE clause to keep the number of

searches down and create suitable indices if necessary. Observations have shown that SAP

HANA is not faster than a traditional database when the WHERE specifies the full primary /

secondary key (when reading buffered data) and SELECTs based on non-key fields can be

much faster with SAP HANA. A selective WHERE-clause is still advisable, but SAP HANA

offers fast scans on all columns.

- Reduce the database Load - e.g. check whether a table meets the criteria for table buffering

(on the application server). Observations have shown that basic rule (still) applies: internal

table

Application Server for HANA (AS ABAP for HANA) - Ramp-Up and general availability

planned for 2013

The well-known SAP NetWeaver Application Server ABAP has been optimized for

running on the SAP HANA in-memory database. This will enable ABAP developers to

build cutting-edge business applications leveraging the proven, reliable ABAP

technology as well as the powerful in-memory capabilities provided by SAP HANA. This

means that AS ABAP can be used for development of new types of SAP applications

(hybrid) based on SAP HANA and on ABAP - custom development that can benefit

from leveraging SAP HANA in the analytical and transactional world.

With the combination of ABAP and SAP HANA, one can optimize existing programs

and build new applications that were not even possible before. Some of the existing

ABAP programming guidelines stay the same, some new development patterns have

emerged and AS ABAP can be used to fully exploit the power of SAP HANA from

within ABAP. According to SAP, AS ABAP is made part of upcoming release SAP

NetWeaver 7.4 (Ramp-Up and general availability planned for 2013).

According to SAP, motivation for AS ABAP comes from different stake holders, especially the

developer, who asks for an Integrated development environment (IDE) comprising all design

time tools as well as an effective and efficient business programming model, which allows to re-

use existing ABAP skill set.

Sample scenario for AS ABAP would look like this :

The SAP HANA platform combines in-memory software with hardware from leading SAP

partners. Adding SAP HANA technology to certified database hardware enables not only

significant acceleration of existing applications, but also the development of completely new

applications that were not previously possible.

Main Features:

AS ABAP Leverages in-memory computing of HANA by using Code Push down technique,

where in calculation logic is pushed down from the application server to the database server. The

SAP HANA database then performs the calculations and sends the resulting data set back for use

by an application.

Traditionally, application logic is executed in the ABAP application server and data is copied

between data and application server. This is an expensive process for data intensive processes.

Using HANA , one can develop optimized applications with data residing in main memory, and

take advantage of massive parallelization with multi-core CPUs

HANA application programming allows to implement Code Push down in the following ways.

SQL script : SQL script is the rich stored procedure language of the SAP HANA database. SQL

script procedures may contain SQL statements and call other procedures. It is used to write

procedural orchestration logic and to define complex data flows.

Example : CREATE FUNCTION divide

( IN x INTEGER,

IN y INTEGER,

OUT result INTEGER,

OUT rest INTEGER

)

TYPE SCALAR

BEGIN

result = @x@/@y@;

rest =@x@-(@result@*@y@);

END;

SELECT divide(sales.totalcount, sales.parts,relcount, rest)

FROM sales;

SQL script function call in ABAP is similar to already existing ABAP, Call syntax. ABAP types

are mapped to native SQL script types according to DDIC type mapping. ABAP internal tables

are mapped to table types. For more details on SQL script, please refer to the SQL Script guide

available at SAP Service market place.

Database Procedures:

These are created using SQL script. These can be called from ABAP report/transaction but is

actually executed at the Database layer.

Example : DATABASE procedure high_and_low

/********* Begin Procedure Script ************/

BEGIN

et_high = select top 5 buyer_guid as bupa_guid from epm.snwd_so order by net_amount;

et_low = select top 5 buyer_guid as bupa_guid from epm.snwd_so order by net_amount desc;

END;

/********* End Procedure Script ************/

Calling this procedure from an ABAP report

REPORT z_high_and_low.

TYPES: ty_guid TYPE x LENGTH 16.

TYPES: BEGIN OF ty,

guid TYPE ty_guid,

END OF ty.

DATA :

ls_high type ty,

ls_low type ty,

lt_high TYPE TABLE OF ty,

lt_low TYPE TABLE OF ty.

CALL DATABASE PROCEDURE /XBR/HIGH_AND_LOW( IMPORTING et_high = lt_high et_low =

lt_low ).

WRITE / 'High'.

LOOP AT lt_high INTO ls_high.

WRITE / ls_high-guid.

ENDLOOP.

WRITE / 'Low'.

LOOP AT lt_low INTO ls_low.

WRITE / ls_flop-low.

ENDLOOP.

HANA modeled views: These are used for defining application specific data models, for defining

data flows, and to structure and re-use queries. Modeled Analytical views and Attribute views

can be created with the SAP HANA studio without programming. ABAP-SQL script integration

can be explained as shown below .

To summarize, till we have ECC on HANA released from SAP for general availability, we could

use the above methods to improve performance of ECC transactions.