database

A database is an organized collection of data, generally stored and accessed electronically from a computer system. Where databases are more complex they are often developed using formal design and modeling techniques.

• RDBMS - Relational Database Management System
• NoSQL - Originally referring to "non-SQL" or "non-relational"

Learn

• Database of Databases Discover and learn about 951 database management systems
• DB-ENGINES Knowledge Base of Relational and NoSQL Database Management Systems
• Awesome data engineering learning path: Awesome list of data engineering learning materials by subject https://awesomedataengineering.com/
• BigData-Notes 大数据入门指南

Tools

• usql A universal command-line interface for PostgreSQL, MySQL, Oracle Database, SQLite3, Microsoft SQL Server, and many other databases including NoSQL and non-relational databases!
• Adminer - Database management in a single PHP file. Supports: MySQL, MariaDB, PostgreSQL, SQLite, MS SQL, Oracle, Elasticsearch, MongoDB, SimpleDB (plugin), Firebird (plugin), ClickHouse (plugin)
• DBeaver: Free multi-platform database tool for developers, SQL programmers, database administrators and analysts. Supports any database which has JDBC driver (which basically means - ANY database). EE version also supports non-JDBC datasources (MongoDB, Cassandra, Couchbase, Redis, BigTable, DynamoDB, etc).
• TablePlus: TablePlus is a native app which helps you easily edit database data and structure. TablePlus currently Supports: PostgreSQL, MySQL, RedShift, MariaDB... High-end security ensured
• Percona Monitoring and Management, A single pane of glass to easily view and monitor the performance of your MySQL, MongoDB, PostgreSQL, and MariaDB databases.
• sysbench is a scriptable multi-threaded benchmark tool based on LuaJIT. It is most frequently used for database benchmarks, but can also be used to create arbitrarily complex workloads that do not involve a database server.