Mastering Regular Expressions

NoSQL Databases

• NoSQL databases provide a mechanism for storage and retrieval of data, modeled in means other than the tabular relations used in relational databases.
• They are used in real-time web applications and big data, and their use is increasing over time.
• NoSQL systems are also sometimes called "Not Only SQL" to emphasize the fact that they may support SQL-like query languages.

Characteristics of NoSQL Databases

• Simplicity of design
• Simpler horizontal scaling to clusters of machines
• Finer control over availability
• Data structures used are different from those used by default in relational databases, making some operations faster
• The suitability of a given NoSQL database depends on the problem it should solve
• Data structures used are sometimes also viewed as more flexible than relational database tables

What is Not NoSQL

• NoSQL does not mean the absence of SQL; instead, it means "Not Only SQL"
• There is no fixed definition for what NoSQL is or does, but the following concepts can help us understand what NoSQL is (and isn't):
  • No relational model
  • Data can be clustered
  • Most solutions are open-source
  • Built for the Web
  • Lack of a schema

Why NoSQL

• Relational databases are not suitable for large amounts of data and changing structures
• Structured data is arranged in neat rows and columns, but unstructured data isn't organized and doesn't follow strict patterns
• NoSQL databases are not tied to a rigid structure and offer things like a clustered approach that can improve performance

SQL vs NoSQL

• SQL: Relational Database Management System (RDBMS)
  • Fixed or static schema
  • Not suited for hierarchical data storage
  • Best suited for complex queries
  • Vertically Scalable
• NoSQL: Non-relational or distributed database system
  • Dynamic schema
  • Best suited for hierarchical data storage
  • Not so good for complex queries
  • Horizontally scalable

Aggregate Data Models

• Used in NoSQL databases
• Flexible data model
• More scalable and performant than relational data models

Limitations of NoSQL

• Joins not supported
• High memory usage
• Limited data size (16MB)
• Limited nesting (100 levels)

MongoDB

• Open-source NoSQL database
• Stores data in JSON-like documents
• Provides high performance, high availability, and automatic scaling
• Uses a distributed database system
• Compromises consistency in favor of availability and partition tolerance
• Uses "eventual consistency" to achieve speed and scalability

MongoDB Query Language

• Uses BSON (Binary JSON)
• Similar to SQL
• Used to query and retrieve data from MongoDB

MongoDB Data Structure Organization

• Database is a physical container for collections
• Each database gets its own set of files on the file system
• A single MongoDB server typically has multiple databases
• Uses name-value pairs or fields, which then make up documents, which make up collections

MongoDB Querying

• Uses the find() method to query and retrieve data
• Can use regular expressions to search for patterns in strings
• Supports arrays and nested documents

Regular Expressions in MongoDB

• Used to search for patterns in strings
• Supports PCRE (Perl Compatible Regular Expression) syntax
• Used to retrieve data that matches a specific pattern

MongoDB Client-Server Architecture

• Uses a client-server architecture
• Server (mongod) should be started before connecting using the client (mongo)
• Client can be used to connect to the server and perform queries

Creating and Using a Database in MongoDB

• Uses the use command to create a new database or switch to a previously created database
• Uses the show collections command to list the collections in the database
• Uses the insert() function to insert data into a collection
• Uses the insertMany() function to insert multiple documents into a collection

Updating and Deleting Data in MongoDB

• Uses the update() function to update data in a collection
• Uses the remove() function to delete data from a collection
• Supports updating and deleting data using criteria and filters

Test your knowledge of regular expressions with this quiz! Learn how to use regular expressions for text search and perform advanced searches with ease. Challenge yourself with examples and practice retrieving specific names using RegEx. Get ready to become a regular expression master!