Graph Gurus Episode 26: Using Graph Algorithms for Advanced Analytics Part 1

Graph Gurus 26
Using Graph Algorithms for Advanced Analytics
Part 1 - Shortest Paths
1

© 2020 TigerGraph. All Rights Reserved
Some Housekeeping Items
● Although your phone is muted we do want to answer your questions -
submit your questions at any time using the Q&A tab in the menu
● The webinar is being recorded and will uploaded to our website shortly
(https://www.tigergraph.com/webinars-and-events/) and the URL will be
emailed you
● If you have issues with Zoom please contact the panelists via chat
2

Today's Presenter
3
Victor Lee
Head of Product Strategy
● BS in Electrical Engineering and Computer
Science from UC Berkeley, MS in Electrical
Engineering from Stanford University
● PhD in Computer Science from Kent State
University focused on graph data mining
● 20+ years in tech industry

Move Faster with TigerGraph Cloud
Built for agile teams who would rather build innovative applications than
procure hardware or configure and manage databases
4

Today’s Outline
5
1
3
2
Graph Analytics - uses and benefits
Shortest Path Algorithms
How to select and use the right one
What are Graph Algorithms?
Overview of different types
4
Demo
GSQL Path Algorithms

Data-Driven Business
Collect more data. See more. Understand more. Decide better.
6

Analyzing Connected Data
● All data processing is "connecting data"
A + B = C
● Linking datasets together enriches your knowledge.
● Statistical Analysis and Machine Learning are about correlation:
seeing how one set of things relates to another set of things.
⇒ Graphs are an ideal way to organize and analyze complex data.
7
Online
sales
In-store
salesStore
Demographics
Web
analytics

© 2020 TigerGraph. All Rights Reserved 8
What is a Graph?
● A Graph is a collection of Vertices and
Vertex-to-Vertex Connections, called Edges
● Each Vertex (sometimes referred to as a node)
and each Edge has a type and characteristic
properties.
● Natural storage model for modeling data and
its interconnections or relationships
● Natural model for representing transactions
● Natural model for knowledge/analysis/
learning – through following and studying
connections
Matt
Customer
Chris
Customer
John
Customer
Bob
Customer
Stephanie
Partner
Jack
Sales
Dan
Partner
Tom
Sales
W
orkswith
Friends
w
ith
Partners
with
W
orkswith
Sells
to
Friends
with
Friends
with
Knows
Product
A
Product
B
Owns
Loves
Bought
Resells
Property Graph

Why Are Graphs Important for Business?
9
100% Annual Growth in Graph through 2022
Graph Named Trend No. 5 on Gartner’s Top 10 Data and Analytics Technology Trends for 2019
What is graph analytics?
A set of analytic techniques that allows for the exploration of relationships between
entities of interest such as organizations, people and transactions.
What’s unique about graph?
Graph data stores can efficiently model, explore and query data with complex
interrelationships across data silos.
Why is graph one of the top 10 trends for data and analytics?
Graph analytics is growing due to the need to ask complex questions across complex
data, which is not always practical or even possible at scale using SQL queries.

Graph algorithms are functions for measuring characteristics
of graphs, vertices, or relationships.
A graph algorithm library serves as a toolkit and as building
blocks for analyzing your data.
Specialized functions Combine to make
something greater
Graph Algorithms
10

GSQL Graph Algorithm Library
● Written in GSQL - high-level, parallelized
● Open-source, user-extensible
● Well-documented
11
docs.tigergraph.com/graph-algorithm-library

Example Questions/Analyses for Graph Algorithms
Which entity is most centrally
located?
● For delivery logistics or greatest visibility
● Closeness Centrality, Betweenness
Centrality algorithms
12
How much influence does this
entity exert over the others?
● For market penetration & buyer
influence
● PageRank algorithm
Which entity has similar relationships
to this entity?
● For grouping customers, products, etc.
● Cosine Similarity, SimRank, RoleSim
algorithms
What are the natural community
groupings in the graph?
● For partitioning risk groups, workgroups,
product offerings, etc.
● Community Detection, MinCut
algorithms

Picking the Right Algorithm for the Job
To become a master designer:
● Learn what each tool can do
● Learn to combine building blocks to solve complex issues
This webinar series is designed to show you what each tool
can do. We'll also show you some application examples.
13

Case Study: Finding Regions of Influence
Step 1: Hub Detection/Ranking - Finding the Influencers
14
Additional details at https://www.tigergraph.com/solutions/product-service-marketing/
Source: Pharmaceutical/Life
Science company seeking the
most influential prescribers.

Case Study: Finding Regions of Influence
Step 1: Community Detection
15
Additional details at https://www.tigergraph.com/solutions/product-service-marketing/

Some Types of Graph Algorithms
● Search
● Path Finding & Analytics
● Centrality / Ranking
● Clustering / Community Detection
● Similarity
● Classiﬁcation
16

Path Analytics
A
B
C
D
E
F
H
G
Is there a path from A to H?
● How many paths?
● What is the shortest or cheapest path?
● What is the degree of separation
(number of hops)?
○ The smaller the degree, the greater
the knowledge/inﬂuence/trust of the other
○ Likelihood of encountering one another
○ Referral for jobs, etc.
● Games:
○ Kevin Bacon number: https://oracleofbacon.org/
○ Erdős number
17

Common Path Questions
● What is the shortest distance from vertex A to vertex B?
● What is a shortest path (sequence of vertices) from A to B?
● Case 1: Unweighted edges
○ We only care if a relationship exists, not how strong or long it is
A
B
C
D
E
F
H
G
18

Shortest Distance in an Unweighted Graph
A
B
C
D
E
F
H
G
Short Distance algorithm:
● Count levels in breadth-first search
● Side benefit: Also finds the shortest
distance to other vertices along the
way
1
1
1
2
2
3
3
function: shortest_distance_unweighted(A, H)
output: 3
19

Shortest Path in an Unweighted Graph
A
B
C
D
E
F
H
G
Short Path algorithm:
● Use breadth-first search
● Record how you got to each vertex
● Variation: return 1 shortest path or
all shortest paths?
A
A
A
A,B
A,C
A,B,E
A,B,E;
A,C,F
function: shortest_path_unweighted(A, H)
output: {A,B,E,H},{A,C,F,H}
● Side benefit: Also finds the shortest
path to other vertices along the way
● Improved version: Search
simultaneously from both source and
destination (bidirectional search)
20

Shortest Path in a Weighted Graph
● Case 2: Weighted edges
○ Each edge has a numerical weight, which is the "cost" to traverse
that edge.
○ Weight could represent distance or elapsed time or cost
A
B
C
D
E
F
H
G
2
4
2
1
2
3
5
2
3
2
3
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Dijkstra's Algorithm for Shortest Path
● Finds a shortest distance or path from a source to every other
vertex.
● Works by assuming the worst case (infinite distance) and then
incrementally finding better (shorter) paths.
● Procedure:
○ Initialize every distance to ∞.
○ Use breadth-first search BUT
go in order of shortest distance.
○ Every time an edge reaches
a destination vertex, update
the shortest distance AND
the path to get there.
● More complex (slower) than unweighted shortest path.
A
B
C
D
E
F
H
G
2
4
2
1
2
3
5
2
3
2
3
22

A
B
C
D
E
F
H
G
2
4
2
1
2
3
5
2
3
2
3
2,A
4,A
2,A
∞
∞
∞
∞
A
B
C
D
E
F
H
G
2
4
2
1
2
3
5
2
3
2
3
2,A
3,AD
2,A
4,AB
6,ADC
∞
∞
23

A
B
C
D
E
F
H
G
2
4
2
1
2
3
5
2
3
2
3
2,A
3,AD
2,A
4,AB
6,ADC|ABE
7,ABE
9,ABE
A
B
C
D
E
F
H
G
2
4
2
1
2
3
5
2
3
2
3
2,A
3,AD
2,A
4,AB
6,ADC|ABE
7,ABE
8,ADCF|ABEF
function: shortest_path_weighted(A, H)
output: {A,D,C,F,H},{A,B,E,F,H}
24

Review: Analytics with Graph Algorithms
● Graph Algorithms answer fundamental questions about
connected data
● Each algorithm in a library is tool in an analytics toolkit.
● Building Blocks for more complex business questions
● Some questions/algorithms are faster or slower than others
25

Practical SW Issues with Graph Algorithms
Wish List:
● Algorithms are functions you can call with your application
● Run the algorithms in-database (don't export the data)
● Option to update the graph with the algorithm results
● Be able to modify/customize the algorithms
● Massively parallel processing to handle big graphs
26

TigerGraph GSQL Graph Algorithm Library
✓ Call each algorithm as a GSQL
function or as a RESTful endpoint
✓ Run the algorithms in-database
(don't export the data)
✓ Option to update the graph with
the algorithm results
✓ Able to modify/customize the
algorithms. Turing-complete
language.
✓ Massively parallel processing to
handle big graphs
27

DEMO
GSQL Graph Algorithms in TigerGraph Cloud
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Real-World Example: Airline Routes
● Dataset: Global commercial airline routes from
openflights.org
○ 7,698 airports
○ 67,664 direct flight routes
● Unweighted search: find the route(s) from A to B with the
fewest stops, ignoring actual distance traveled
○ Simplifications: not considering actual flight schedules or which
airlines or prices
● Add weight: distance from city to city
○ BUT dataset doesn't have that info. Write a simple GSQL to
calculate the distance, based on locations of source and
destination, and add it to the graph data
● Weighted search: find the shortest route from A to B
29

Enhancements
(Might or might not do, if we have time to develop and time to
demo)
● ALL the shortest routes (e.g., there might be multiple 1-stop
routes from Des Moines to Cleveland
● Find the Top K shortest routes
● Find routes only on a given airline
● Find multi-hop routes that don't change airlines
30

Summary
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1
4
3
Graph Algorithms - tools and building
blocks for analyzing graph data
GSQL Algorithm Library - runs
in-database, high-performance,
easy to read and modify
Shortest Path Algorithms - different
algorithms for weighted and
unweighted graphs
2 Learning To Use Algorithms - know what
problem they solve, pros and cons

Q&A
Please submit your questions via the Q&A tab in Zoom
32

More Questions?
Join our Developer Forum
https://groups.google.com/a/opengsql.org/forum/#!forum/gsql-users
Sign up for our Developer Ofﬁce Hours (every Thursday at 11 AM PST)
https://info.tigergraph.com/officehours
33

Additional Resources
Start Free at TigerGraph Cloud Today!
https://www.tigergraph.com/cloud/
Test Drive Online Demo
https://www.tigergraph.com/demo
Download the Developer Edition
https://www.tigergraph.com/download/
Guru Scripts
https://github.com/tigergraph/ecosys/tree/master/guru_scripts
34

Upcoming Graph Guru Events
35
Coming to Dallas, Houston, Austin, Seattle, San
Francisco… and Munich! More are in the works.
View all events and request your own here:
https://www.tigergraph.com/graphguruscomestoyou/
Graph Gurus 27: An In-Database Machine
Learning Solution For Real-Time Recommendations
https://info.tigergraph.com/graph-gurus-27

Graph Gurus Episode 26: Using Graph Algorithms for Advanced Analytics Part 1

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Graph Gurus Episode 26: Using Graph Algorithms for Advanced Analytics Part 1