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Module 4 - Review

Module Overview

Review key concepts from this sprint and prepare for the sprint challenge, focusing on graphs, service design, and relational databases.

Sprint Review Summary

This sprint covered three main topic areas: Graphs, Service Design, and Relational Databases. Let's review the key concepts from each area to help you prepare for the sprint challenge.

Graphs

Graphs are versatile data structures consisting of nodes (vertices) connected by edges. They're ideal for representing relationships and connections in data.

Key concepts:

Nodes (vertices) and edges (connections between nodes)
Directed vs. undirected graphs
Weighted vs. unweighted edges
Cycles in graphs
Graph traversal algorithms: Breadth-First Search (BFS) and Depth-First Search (DFS)
Graph representations: adjacency matrix and adjacency list

For the sprint challenge, be prepared to design a graph-based solution to a business problem, implement graph traversal algorithms, and analyze graphs for properties like connectivity and cycles.

Service Design

Service design focuses on creating scalable, maintainable systems that solve business problems through the optimal organization of components and technologies.

Key concepts:

Service design principles: don't reinvent the wheel, simplicity over complexity
Component-based architecture
Design patterns: adapter, facade, proxy, notifier, and aggregator
Trade-off analysis between different design options
AWS compute options: Lambda, ECS, EC2
Lambda limitations and appropriate use cases

The sprint challenge may ask you to analyze a business scenario, recommend an appropriate service design, and justify your choice with a trade-off analysis.

Relational Databases

Relational databases organize data into tables with fixed schemas, using keys to establish relationships between tables.

Key concepts:

Tables, records, columns, and schemas
Primary keys and foreign keys
Data types: numeric, date, varchar, boolean
Normalization to reduce data redundancy
Referential integrity constraints
Database associations: one-to-one, one-to-many, many-to-many
SQL queries: SELECT, JOIN, WHERE clauses

For the sprint challenge, expect to write SQL queries, design normalized database schemas, and interpret entity relationship diagrams.

Remember to review the code-alongs and exercise solutions from each module. These practical examples will help solidify your understanding of the concepts and prepare you for the hands-on aspects of the sprint challenge.

Learning Objectives Review

Graphs

Assemble a graph from provided relationships
Analyze whether a graph models a provided business problem
Identify cycles in a provided graph
Analyze whether a directed or undirected graph models a provided business problem
Manually perform a breadth-first traversal of a graph to find the shortest path from one node to any node that satisfies a given condition
Manually perform a depth-first traversal on a graph to perform an operation on each node
Outline the purpose of a Graph
Compare and contrast the Graph and Tree data structures

Service Design

Identify whether AWS Lambda should not be used as the architecture for a set of business requirements
Identify trade-offs of using each of a set of alternative technologies in a provided design document to solve a specified business problem
Make a service design recommendation based on a trade-off analysis
Compare Lambda against other AWS Compute options
Outline the use case for the adapter, facade, proxy, notifier, and aggregator service design patterns

Relational Databases

Recall that tables in a relational database have a fixed schema that every record must satisfy
Recall that relational databases use NULL to specify that a record does not have a value for a specific column
Recall that relational databases include numeric, date, varchar, and boolean representations of data
Identify a unique record in a provided table by its primary key's value
Recall that normalization reduces redundant data while enabling data consistency
Recall that relational databases use foreign keys to enforce referential integrity
Outline when an insert will fail in a relational database due to referential integrity constraints
Recall that relational databases, unlike non-relational databases, have a fixed schema, maintain referential integrity, and enable joining across tables
Outline referential integrity in relational databases
Identify foreign and primary key pairs from a given entity relationship diagram
Write an SQL statement that retrieves rows satisfying specified conditions from a single table
Write an SQL statement that counts the number of rows satisfying specified conditions in a table
Write an SQL statement that describes a table's columns
Determine the results of executing a provided SQL select statement on a given table
Write an inner join SQL statement that retrieves rows satisfying specified conditions
Predict the results of executing a provided inner join SQL statement on a set of given tables
Implement an SQL statement to answer a provided business question, given an entity relationship diagram
Write an SQL statement that retrieves only specified columns from a single table
Explain inner join in relational databases

Module 4 - Review

Module Overview

Sprint Review Summary

Graphs

Service Design

Relational Databases

Learning Objectives Review

Graphs

Service Design

Relational Databases

Resources