Datastore core concepts

Before going any further, let's take a step back and look at how Datastore actually works. Datastore is designed to be easy to use, but there are several concepts that may be unfamiliar to many developers. In order to get the most out of Datastore, it's important to understand a few core concepts, such as how the data is modeled, how indexing works, and under what circumstances Datastore offers atomicity, consistency, isolation, durability (ACID) compliance.

The structure of Datastore data

Most developers are familiar with the general structure of data in a traditional relational database, and a common approach to understanding Datastore is to build on that knowledge by drawing parallels between relational databases and Datastore. Here is a table outlining the base components of each system and how they relate:

Relational databases	Datastore
Table	Kind
Row	Entity
Column or field	Property
Primary key	Identifier, key
Foreign keys	Ancestors and descendants

 

Note that each of these...