This document provides an overview of a summer school on databases. It discusses why databases are needed, the history of navigational and relational databases, relational algebra, normalization, structured query language, database storage, transactions, relational database management systems, object-relational mapping, multidimensional data, business intelligence, NoSQL databases, Brewer's theorem, NoSQL database products, and other database types. The document is meant to educate attendees on the fundamentals and modern applications of databases.

1. Summer School 2012
Databases
Yuriy Guts
R&D Engineer
yuriy.guts@eleks.com

2. Summer School 2012
Why do we need databases?
Try answering this question:
Why do we need computers?
?? ?

3. Summer School 2012
Why do we need databases?
Computer Science
Is it a science?
Is it about computers?
“Datalogy” — Peter Naur, 1961

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Navigational databases (1960-s)

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Relational databases (1970-s)

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Relational Algebra 101
Set Union Natural Join
Set Intersection Equi-Join
Cartesian Product Semi-Join
Projection Anti-Join
Selection Division
Rename Outer Join

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Entity Relationship & (De)Normalization
Association Cardinality
• One-to-one
• One-to-many
• Many-to-many
Normal Forms
• 1NF • 4NF
• 2NF • 5NF
• 3NF • DKNF
• BCNF • 6NF

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Structured Query Language (SQL)

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Storage: B-Tree, Indexing

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Database as a Concurrent Storage
Transaction Properties (“ACID”)
A Atomicity
C Consistency
I Isolation
D Durability
Although transactions can have different isolation levels!
Lower levels can improve performance, but with a price (side effects)

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Relational DBMS Products

12. Object-Relational Mapping (ORM)

13. Object-Relational Mapping (ORM)

14. ORM: Example (Entity Framework)

15. ORM: Design Approaches
Database First
Model First
Code First

16. Does life exist beyond RDBMS?

17. Multidimensional Data

18. Business Intelligence
• Data Analysis
• Performance Measurement
• Enterprise Reporting
• Knowledge Management
• Data Mining

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NoSQL Databases
Key-Value Store Document Store Multivalue Store
Graph Store Object Database RDF Database

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Brewer Theorem (“CAP Theorem”)
A distributed computer system
cannot provide all three of the following:
C Consistency
A Availability
P Partition Tolerance
Common case: “Eventual Consistency” databases

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NoSQL Database Products

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Some More DB Types
Active Embedded Knowledge
Cloud Federated Parallel
Data Warehouse Hypermedia Real-time
Distributed Hypertext Spatial
Document In-memory Temporal

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?? ?
Q&A
yuriy.guts@eleks.com

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Thank you!