1. QUERY PROCESSING
1.1. SQL – Structured Query Language -commands that use to access data within databases. - DDL - DCL - DML
2. Data Control Language
3. DML COMMANDS
3.1. Data Manipulation Language
3.2. INSERT INTO
3.3. DELETE
3.4. SELECT
3.4.1. FROM
3.4.1.1. WHERE
3.5. UPDATE
4. CONSTRAINTS
4.1. PRIMARY KEY
4.2. FORIEGN KEY
4.3. UNIQUE KEY
4.4. NOT NULL
5. DDL COMMANDS
5.1. Data Defination Language
5.2. CREATE
5.3. ALTER
5.4. RENAME
5.5. ADD
5.6. MODIFY
5.7. DROP
6. DATABASE SYSTEM INTERNALS
7. DCL COMMANDS
7.1. GRANT
7.2. REVOKE
8. DATA MANAGEMENT
8.1. Permenant
8.2. Temporary
9. DATA MODELS
9.1. STRUCTURED
9.1.1. organized and formatted in a way so it's easily searchable in relational databases. Examples of structured data - names, dates, addresses, credit card numbers, - geolocation etc.
9.1.1.1. Relational DB(RDBMS) - MySQL - Microsoft SQL Server -Oracle Database
9.2. UNSTRUCTURED
9.2.1. no pre-defined format or organization, making it much more difficult to collect, process, and analyse. Examples of unstructured data -text, video, audio, mobile activity, social media activity, satellite imagery, surveillance imagery etc.
9.2.1.1. Non-relational DB (NoSQL databases) - MongoDB - Cassandra -HBase
9.3. SEMI-STRUCTURED
9.3.1. form of structured data that does not conform with the formal structure of data models associated with relational databases or other forms of data tables. It is called self-describing structure. Examples of semi-structured data - JSON and XML.
9.4. METADATA
9.4.1. data about data. It provides additional information about a specific set of data. Example of metadata - for a photograph, metadata could describe when(date) and where(location) the photos were taken.