REST promotes CRUD. CRUD is for databases, not applications.

Databases generally have four operations to a set of data: Create, Read, Update, and Delete; these four operations are known by the acronym CRUD. An SQL-based relational database (like PostgreSQL, MySQL, etc.) have 4 cooresponding statements:

• Insert -> Create
• Select -> Read
• Update -> Update
• Delete -> Delete

The CouchDB database and SOLR search engine operate natively over a REST interface. Your applications perform CRUD operations on these data stores by employing the above style of request.

Architectures based on REST, like Ruby on Rails, builds the application on table resources to perform CRUD operations. By doing this, we get a free API into the application callable from any platform capable of making HTTP/REST calls.

Many applications require users to register or enter their email addresses. As good, standards-compliant developers, we want to validate and accept these email addresses using RFC standards. We think it will help us in the future, and make our app a shining beacon of usability to be admired.

Wrong.

Deploying PostgreSQL in a high-demand environment requires reliability and scalability. PostgreSQL’s ecosystem offers the tools you need to build out a robust database system. This guide offers a high-level description of tools used to build a high-availability, scalable, fault-tolerant service.

These tools are explained:

• PostgreSQL Database with Streaming Replication
• Pgpool-II multipurpose connect proxy for PostgreSQL
• PgBouncer connection pooler for PostgreSQL
• Repmgr - Replication Manager for PostgreSQL Clusters

Resque is a fast, lightweight, and powerful message queuing system used to run Ruby jobs asynchronously (or in the background) from your on-line software for scalability and response. I needed to integrate software written in different languages and environments for processing, and this is my understanding of the implementation.

Recently, NoSQL data stores have been getting a lot of attention, as an alternative to using a relational database. They allow more complex data structures to be stored and queried than you find in the table-row-column model.

The PostgreSQL relational database server has several data features that you would expect to be found only in the NoSQL data stores.