Entity Attribute Values

Learn about creating tables, inserting data into tables, and the pros and cons of EAV.

We'll cover the following

Creating a table
Inserting data
Problems of EAV anti-pattern
A quick design for new tables
Using joins in EAV

Failure to follow normalization forms open the door to anomalies. Some failure modes are so common in the wild that we can talk about anti-patterns. A bad design choice would be the EAV model.

The entity attribute value (EAV) is a design that tries to accommodate a lack of specifications.

Creating a table

In our application, we have to deal with parameters, and new parameters may be added at each release. It’s not clear which parameters we need, we just want a place to manage them easily, and we’re already using a database server, after all. So there we go:

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Part I: Preface

Introduction to PostgreSQL

Part II: Introduction to Structured Query Language

Part III: Writing SQL Queries

Business Logic

A Small Application

The SQL REPL: An Interactive Setup

Indexing in PostgreSQL

Part IV: SQL Toolbox

SQL Tools

Managing Output in SQL

Understanding Nulls

Window Functions

Relations and Joins

Part V: Data Types

Serialization and Deserialization

PostgreSQL Data Types 101

Denormalized Data Types

Part VI: Data Modeling

Object Relational Mapping and Tooling for Database Modeling

Normalization

Practical Use Case: Geonames

Modelization Anti-Patterns

Denormalization

Not Only SQL

Part VII: Data Manipulation and Concurrency Control

Another Small Application

Isolation and Locking

Computing and Caching in SQL

Triggers

Listen and Notify

Batch Update, MoMA Collection

Part VIII: PostgreSQL Extensions

What’s a PostgreSQL Extension?

Auditing Changes with hstore

Million Song Dataset

Using Trigrams for Typos

Denormalizing Tags with intarray

The Most Popular Pub Names

Geolocation with PostgreSQL

Counting Distinct Users with HyperLogLog

Appendix

Entity Attribute Values

Creating a table