Presentation at RailsWayCon 2011 conference

1. Raimonds Simanovskis
Multidimensional
Data Analysis
with JRuby

2. Raimonds Simanovskis
github.com/rsim
@rsim
.com

3. Relational
data model

4. SQL is good for detailed
data queries
Get all sales transactions in
USA, California
SELECT customers.fullname, products.product_name,
sales.sales_date, sales.unit_sales, sales.store_sales
FROM sales
LEFT JOIN products ON sales.product_id = products.id
LEFT JOIN customers ON sales.customer_id = customers.id
WHERE customers.country = 'USA' AND customers.state_province = 'CA'

5. SQL becomes complex
for analytical queries
Get total sales in USA, California
in Q1, 2011 by main product groups
SELECT product_class.product_family,
SUM(sales.unit_sales) unit_sales_sum,
SUM(sales.store_sales) store_sales_sum
FROM sales
LEFT JOIN product ON sales.product_id = product.product_id
LEFT JOIN product_class
ON product.product_class_id = product_class.product_class_id
LEFT JOIN time_by_day ON sales.time_id = time_by_day.time_id
LEFT JOIN customer ON sales.customer_id = customer.customer_id
WHERE time_by_day.the_year = 2011 AND time_by_day.quarter = 'Q1'
AND customer.country = 'USA' AND customer.state_province = 'CA'
GROUP BY product_class.product_family

6. If SQL is not good
then we need
NoSQL!

7. Maybe write distributed
map reduce function?
http://browsertoolkit.com/fault-tolerance.png

8. Multidimensional
Data Model
Multidimensional cubes
Dimensions
Hierarchies and levels
Measures

9. OLAP technologies
On-Line Analytical Processing

10. Commercial Vendors
Oracle Essbase SAP BUSINESSOBJECTS
Oracle OLAP
Cognos
Analysis Services

12. MDX query language
Get total units sold and sales amount
in USA, California in Q1, 2011
by main product groups
SELECT {[Measures].[Unit Sales], [Measures].[Store Sales]} ON COLUMNS,
[Product].children ON ROWS
FROM [Sales]
WHERE ( [Time].[2011].[Q1], [Customers].[USA].[CA] )

13. http://github.com/rsim/mondrian-olap

14. (R)OLAP schema
Dimensional model:
cubes
dimensions (hierarchies & levels)
measures, calculated measures
Mapping
Relational model:
fact tables, dimension tables
joined by foreign keys

15. OLAP schema
definition
schema = Mondrian::OLAP::Schema.define do
cube 'Sales' do
table 'sales'
dimension 'Gender', :foreign_key => 'customer_id' do
hierarchy :has_all => true, :primary_key => 'customer_id' do
table 'customer'
level 'Gender', :column => 'gender', :unique_members => true
end
end
dimension 'Time', :foreign_key => 'time_id' do
hierarchy :has_all => false, :primary_key => 'time_id' do
table 'time_by_day'
level 'Year', :column => 'the_year', :type => 'Numeric', :unique_members => true
level 'Quarter', :column => 'quarter', :unique_members => false
level 'Month',:column => 'month_of_year',:type => 'Numeric',:unique_members => false
end
end
measure 'Unit Sales', :column => 'unit_sales', :aggregator => 'sum'
measure 'Store Sales', :column => 'store_sales', :aggregator => 'sum'
end
end

16. Query Builder in
Ruby
Get total units sold and sales amount
in USA, California in Q1, 2011
by main product groups
olap.from('Sales').
columns('[Measures].[Unit Sales]',
'[Measures].[Store Sales]').
rows('[Product].children').
where('[Time].[2011].[Q1]', '[Customers].[USA].[CA]').
execute

17. Also more complex
queries
Get sales amount and profit %
of top 50 products sold in USA and Canada
during Q1, 2011
olap.from('Sales').
with_member('[Measures].[ProfitPct]').
as('(Measures.[Store Sales] - Measures.[Store Cost]) / Measures.[Store Sales]',
:format_string => 'Percent').
columns('[Measures].[Store Sales]', '[Measures].[ProfitPct]').
rows('[Product].children').crossjoin('[Customers].[Canada]', '[Customers].[USA]').
top_count(50, '[Measures].[Store Sales]')
where('[Time].[2011].[Q1]').
execute

18. Demo

19. Used in eazybi.com