1. Allegro’s DWH Implementation on
Oracle Database Machine
with OWB & OBIEE
Rafał Kudliński, BI Manager Allegro Group

2. Allegro Group operates market leading e-commerce trading platforms; general, automotive and real
estate classified sites; a price comparison site; and payment web services across Eastern Europe
under various brands. Allegro Group operates 46 platforms in 13 countries.
Do you really know Allegro?
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Rafał Kudliński – BI Manager Allegro Group

3. Allegro is the most successful eCommerce trading system in Poland and the largest non-eBay auction
platform worldwide.
Do you really know Allegro?
MORE THAN 14.5 1000 EMPLOYEES
MILLION USERS
250 employees in the
Over 9500 new users IT department:
every day. 150 in the
Over 3.5 million new development division
users every year. and 100 in other IT
divisions (IS, DWH,
R&D, etc.).
MORE THAN 500 MORE THAN 90
MILLION PAGE MILLION LISTED
VIEWS (Peak) ITEMS
The number of page The number of listed
views has doubled items has increased
within the last 3 years. by 75 million over the
past 3 years.
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Rafał Kudliński – BI Manager Allegro Group

4. Our figures are extraordinary in all areas. We use a leading-edge technology wherever possible. The
power consumption of our DCs is bigger than 800 average households together!
Do you really know Allegro?
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Rafał Kudliński – BI Manager Allegro Group

5. We decided that measuring our internet services performance is most important for our business
growth. It covers both services and user areas. We have to really understand what is happening on
our websites and who is our most valuable user.
Business requirements (Priority 1)
What is our internet services performance?
We need to play with data, simulate and have influence on growth; Users
expecting quality and we are expecting more sales; We need to measure
the categories?; We need to know if our pricing model is optimal?; We
need to know when the growth is getting slowed down? What influence the
success rate for auctions for different categories? We need to know our
refunds, fees; We need to analyse the method of payment; Auctions on
the front page and we need to analyse the conversion rate and why? We
want to measure the effect of the changes in the categories; We need to
benchmark countries; What products are sold most frequently ? new or
used? What is source of our profit?; What is result of search? What user
do after that? We need to know where user click and what he do on our
site?
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Rafał Kudliński – BI Manager Allegro Group

6. The Operational performance and marketing campaign effectiveness is also crucial to our business.
Co brand and affiliate programs as valuable sources of traffic and new users registrations have to be
carefully monitored as well.
Business requirements (Priority 2 and 3)
What is our operational performance?
We need to do our job faster, better, more efficient; we need to know which
projects to realize, which are profitable; We need to measure the activity?
What is our Marketing campaigns performance?
(We need to measure the campaigns?; We need to know effect of
marketing action? source of traffic? need to track the result of our
spending.
What is our co-brand performance?
What are the sources of new registrations?
What is our Affiliate Performance?
We need to know affiliation program impact?
What is offered Products performance?
We need to measure products?
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Rafał Kudliński – BI Manager Allegro Group

7. Agenda
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Rafał Kudliński – BI Manager Allegro Group

8. The first project took 6 months to complete, with 8 people working on it. Support from external companies
was necessary due to the implementation of a new technology and software.
Projects in Numbers
Project duration : 12 months
Project team: 8 – 12 people
Man/days spent: 800
Active Users – 120
Implemented reports – 100
Implemented KPIs – 160
Biggest source system size – 7TB
Largest Tables – 2.8 billion records
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Rafał Kudliński – BI Manager Allegro Group

9. We load data from a real time copy of the production system. Extraction and transformation processes
are performed to load data to DWH production scheme. Finally aggregations are built to improve query
processing performance. We use OWB as ETL tool.
Data warehouse architecture
Allegro Logical
Production Standby Load DWH Staging Area ETL DWH Production
Oracle DB Oracle DB Oracle DB Oracle DB
Oracle Data Guard
Production Environment
ETL
2 * IBM P590 Machine
DB 1 DB 2 ..
MySql
DB ..10
MySql
OWB
MySql DataMart
Oracle DB
Click Stream recording
Environment Data Warehouse Environment
10 * DL360 Machine Oracle Database Machine
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Rafał Kudliński – BI Manager Allegro Group

10. We use Oracle Business Intelligence Enterprise Edition as BI tool. OBIEE is connected to both Target
and DataMart schemas. We have almost 120 active users. 10 power users perform Ad- hoc queries.
Allegro DWH & BI system architecture
Interactive
Dashboards
DWH Production Ad-hoc
Oracle BI Server
Oracle BI Server
Target Analysis
Transaction
Platforms
Delivers
DWH Production and Alerts
DataMart
Data Warehouse Environment MS Office
Oracle Database Machine Plug-in
Other Oracle 11g
Systems
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Rafał Kudliński – BI Manager Allegro Group

11. BI Portal presents the most important reports / KPIs describing performance of our major auction
platforms in all countries we operate. We can find there information about open auctions, registered
users, bids, sales and charges.
Allegro Performance KPIs
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Rafał Kudliński – BI Manager Allegro Group

12. Product managers can analyze a number of measures drilling down in the product category tree. They
can filter data by selecting an auction type or a seller type.
Auction Category Analysis
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Rafał Kudliński – BI Manager Allegro Group

13. BI Portal contains also information about IT department performance. Managers can see current
budget realization, SLA, Traffic and status of most important current IT projects.
IT Department KPIs
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Rafał Kudliński – BI Manager Allegro Group

14. We deliver information about the number of clicks grouped by users, user locations, services, scripts and,
most importantly (not available yet), by product categories. The users can drill down to detail information.
Click Stream analysis
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Rafał Kudliński – BI Manager Allegro Group

15. DB Machine is very efficient in all types of ETL processing. We do parsing, cleaning, merging and joining
of almost 500 million records each day. The number of aggregation tables is calculated and refreshed.
Lesson 2 – ETL Processing – DB Machine do it all
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Rafał Kudliński – BI Manager Allegro Group

16. As usual, in order to have excellent performance, you have to think about partitioning, compression and
parallel query execution. No indices; full table scan performance needs to be considered.
Lesson 3 – Data Architecture – Standard but Improved
We use Standard Star Schema with a collection of fact tables
Our largest fact tables have almost 3 billion records (billings, clicks)
Our largest dimension tables have more than 15 million records (users,
locations)
No Indices - no need; in some cases using them was even worse
Full Table Smart Scan – works very efficiently
We heavily use partitions (days, months) and sub-partitions (attributes)
Compression – saves space (avg. 30%) and improves performance
Parallel query execution /*+parallel(table,8,3)*/ - works very well – average
query execution time improvement = X10
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Rafał Kudliński – BI Manager Allegro Group

17. Even when using DB Machine, it is necessary to use the aggregation tables to achieve necessary user
interface performance. What you get is scalable and fast aggregation and reporting environment.
Lesson 4 – User Access – fast and reliable
We create a number of aggregation tables to avoid joins between million-
record tables
Reports and dashboards are delivered within seconds (<5s) even with >100
users working
OBIEE works very well with DB Machine especially in reporting and
dashboarding
OBIEE ad-hoc Answers application is very powerful but still some users need
to use SQL to get what they want (automatically generated queries are not
adjusted to use all DB machine features)
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Rafał Kudliński – BI Manager Allegro Group

18. Exadata storage server brings an additional value but not many additional tasks. It can be handled by
DBA without any special skills
Lesson 5 - DB Administration – no complexity
Just typical RAC environment
Fully integrated with Grid Control – storage cell monitored with a dedicated
plug-in
Distributed command execution
Easy storage layer administration – replace/create a disk/diskgroup with no
more than 3 commands
Comprehensive command shell on a storage cell
Additional hardware/software components needed for integration with SAN
backup environment.
Self-monitoring storage layer with email notifications
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Rafał Kudliński – BI Manager Allegro Group

19. Support from Oracle and external experienced consultants is necessary for successful DW & BI
implementation (using new environment)
Lesson 7 – External support – helps and speeds up
Business Needs
Business Discovery (performed with the help of Oracle Consulting ) was very
valuable to prioritize business requirements - Jamal El Faiz
ETL Process
Experience in massive data processing from ISE – Igor Michaljow
OBIEE
Expertise in building robust reports and dashboards from Oracle Consulting
Alessandro Sabelli, Małgorzata Baran, Marzena Krzanowska
DB Machine administration
Some initial configuration made by Oracle
Support from RAC PAC team (best practices, service requests)
Update Patches are frequently released
Experienced internal DBA is crucial – Wojciech Semenowicz
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Rafał Kudliński – BI Manager Allegro Group

20. Right now we are working on processing Click Stream data to DWH. We have more than 400 mln page
views every day. In next few months data from our payment and classified services will be loaded .
Next Steps and Outlook
FUTURE
PRESENT
PAST
PAST
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Rafał Kudliński – BI Manager Allegro Group

21. Recommendations
Thing big act small and before you start search for the right staff!
Plan and manage project carefully
Have right sponsor and support from business site
Oracle Database Machine is definitely right choice
At the beginning Support from Oracle consulting is crucial
Stand for Information Democracy in your company
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Rafał Kudliński – BI Manager Allegro Group

22. Q&A
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Rafał Kudliński – BI Manager Allegro Group