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Cubes is light-weight online analytical processing (OLAP) framework and HTTP OLAP service server. Documentation: http://packages.python.org/cubes/
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Features
■ logical model (metadata)
■ aggregated data browsing
■ OLAP HTTP server with json interface
■ data and metadata localization
■ multiple backends
Introductioncubes, facts and dimensions
data cube
data cell
data cell
fact
most detailed
information
Fact examples:
• contract
• donation
• spending
• invoice
• project
• ...
measurable
measure examples:
• contract amount
• revenue
• duration
• price with VAT
dimensions
location
type
time
dimensionslocation
type
time
■ provide context for facts
■ used to filter queries or reports
■ control scope of aggregation of facts
■ used for ordering or sorting
■ define master-detail relationships
☛ [star]
hierarchies
May
region
date
1st2010
data mart
subject area
Summary
■ fact – most detailed information for analysis
■ measure – an attribute for computation
■ dimension – context of facts
■ hierarchy – master-detail relationship
Slicing and Dicing✂
✂
2010
2009
2008
2007
2006
spending in 2010
location
type
time
Estonia
Poland
HungarySlovakia
Czech Republic
contracts in
Estonialocation
type
time
location
type
time
contracts in
Estonia in 2010
Estonia 2010
✂
✂
location
type
time
IT contracts
location
type
time
IT contracts in
Estonia in 2010
Estonia 2010
IT✂
✂
✂
measures can be aggregated
spending in 2010
revenue from IT
projects
top 10
contractors
Drilling down
0
35
70
2006 2007 2008 2009 2010
6070
4050
30
0
125
250
All years
250
∑amount
drill down by date
∑amount
looking at more detailed level
0
35
70
2006 2007 2008 2009 2010
6070
4050
30
0
125
250
All years
250
0
3,5
7
Jan Feb Mar Apr March April May ...1
3
7
1
54
23
top level
year level
month level
Logical Modeldescription based on how you analyze data
Logical Modeluser’s or analyst’s perspective:
how data are being
measured, aggregated and reported
24%
28% 16%
20%
12%∑amountamount
✶ star❄ snowflake
abstraction over physical data
!
Legend:"#localizable!#required during cube creation
and denormalisation$#required by browser
description "
default hierarchy
label "name
Dimension
detailsfact table !
measures
description "label "name
Cube
label "name
Hierarchy
label attributekey attribute
label "name
Level
description "locales !$
label "name
Attribute
locale
description "label "name
Model
masterdetailalias
Join !
masterdetail
Mapping !
SlicerCubes OLAP server
Slicer
Aggregation Browser
Cell(point of view)
facts(details)
∑ aggregates
Application
HTTP request
JSON reply
model
model
GET /model{ "cubes": { "contracts": { "measures": [ { "name": "amount", "label": "Contract amount" } ], "dimensions": ["date", "supplier", "process_type", "cpv"] } }, "dimensions": { "supplier": { ... } } ...}
GET /aggregateaggregate measures
GET /aggregate
∑amount
GET /aggregate
{ "drilldown": {}, "summary": { "record_count": 19278, "zmluva_hodnota_sum": 11222821530.12966 }}
cut=...slice and dice with cut parameter
GET /aggregate?cut=date:2010
∑amount
✂
2010
GET /aggregate?cut=date:2010✂
2010
{ "drilldown": {}, "summary": { "date.year": 2011, "record_count": 64, "zmluva_hodnota_sum": 78717997.108
}}
/aggregate?cut=date:2010|region:ee
∑amountEstonia
2010
✂
✂
cut
cut=date:2010|region:es
dimension points
dimension points
date:2010
region:ee
dimensionpath
hierarchies
date:2010,12
dimensionpath
month level
year level
more hierarchies
date:2010,12|category:it,sw|
region:ee
contracts in December 2010
in Estonia for IT – Software
cut
date:2010,12|category:it,sw|region:ee
pipe separates cuts
comma separates levels
PUT /reportif you want multiple tables and charts with single
request
drilldown=get more details
0
35
70
2006 2007 2008 2009 2010
6070
4050
30
0
125
250
All years
250
∑amount
∑amount
drilldown=date
0
35
70
2006 2007 2008 2009 2010
6070
4050
30
0
125
250
All years
250
0
3,5
7
Jan Feb Mar Apr March April May ...1
3
7
1
54
23
drilldown=date
cut=date:2010 &drilldown=date
implicit
hierarchy
drilldown=date
drilldown=date&cut=date:2010
drilldown=date&cut=date:2010,11
report by year:
report by month:
report by day:
drilldown=date,supplier
more dimensions:
for cross-tables
Atributes and Measuresnaming
dimensionattribute
category.description
date.yeardate.month
region.region_name
region.region_coderegion.city_name
hierarchical attribute dependencies are implicit
defined in model
there is no “date” data typedate components are normal attributes of
date dimension
month dayyear
received_amount_sum
record_count
measure aggregation
page=...&order=ordering and pagination
page=3&pagesize=20
3rd page with 20 results per page
order=region.nameorder by region name
order=amount:descorder by amount descending
Natural Ordering
attributes can have default order specified in model
order=year:asc
... might be omitted if model contains:
{“name” = “year”, “order” = “asc”}
lang=transparent localization
Localization
1
2
3
+ +
master model translations
drilldown=type&lang=endrilldown=type&lang=sk
report query is language independent
Cubesonline analytical processing
github/bitbucket: Stiivi
☛ References
[star] Christopher Adamson: Star Schema, 2010
and further reading
