Data and Database

A database is an organized collection of data, generally stored and accessed electronically from a computer system.

Includes knowledge areas

Relational DB

A relational database is a type of database. It uses a structure that allows us to identify and access data in relation to another piece of data in the database. Often, data in a relational database is organized into tables. There are most popular of them — SQL Server, PostgreSQL, MariaDB, MySQL, SQLite, Oracle, etc.


A NoSQL (originally referring to "non-SQL" or "non-relational") database provides a mechanism for storage and retrieval of data that is modeled in means other than the tabular relations used in relational databases. Talking about NoSQL DB is nice to know about CAP/PACELC, Key-value, document-oriented, column-oriented, map-reduce, graph-db, real-time, multi-model. The are plenty of NoSQL DBs and management systems: MongoDB, Redis, LiteDB, Apache Cassandra, RavenDB, CouchDB, etc.

Cloud Database

A cloud database is a database that typically runs on a cloud computing platform and access to the database is provided as-a-service. Depends of the cloud could be different databases: Azure CosmosDB, Amazon DynamoDB etc.

Search Engines

A powerful search engine behind your database helps the customers in better finding. Here is nice to know ElasticSearch, Solr,  Lucene, Indexing/Tokenization, Indexes, Ranking, Heavy Load, etc.


Set of properties that a database transaction in a relational database is supposed to have (Atomicity, Consistency, Isolation, Durability)


A transaction can be defined as a group of tasks. A single task is the minimum processing unit which cannot be divided further.

N+1 Problem

The N+1 query problem happens when your code executes N additional query statements to fetch the same data that could have been retrieved when executing the primary query.

Database Normalization

Database normalization is the process of structuring a database, usually a relational database, in accordance with a series of so-called normal forms in order to reduce data redundancy and improve data integrity. It was first proposed by Edgar F. Codd as part of his relational model.

Indexes and how they work

A database index is a data structure that improves the speed of data retrieval operations on a database table at the cost of additional writes and storage space to maintain the index data structure.

DB design

This skill is nice to have while working with high-loaded RDBMS. DB design means you know how to read, write optimizations, aware of Scalability, partitioning replication, indexing, and other stuff.

Data Migration (ALEMBIC)

Alembic is a lightweight database migration tool for usage with the SQLAlchemy Database Toolkit for Python.

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The rich text element allows you to create and format headings, paragraphs, blockquotes, images, and video all in one place instead of having to add and format them individually. Just double-click and easily create content.

Static and dynamic content editing

A rich text element can be used with static or dynamic content. For static content, just drop it into any page and begin editing. For dynamic content, add a rich text field to any collection and then connect a rich text element to that field in the settings panel. Voila!

How to customize formatting for each rich text

Headings, paragraphs, blockquotes, figures, images, and figure captions can all be styled after a class is added to the rich text element using the "When inside of" nested selector system.