Azure DP-900 Short Notes: Describe concepts of relational data
Understand the characteristics of relational data
👉Relational data model collections of entities from the real world as tables.
👉A table consist of row and columns where each row represent a single entity.
👉A single table consist of a Primary key.
👉A foreign key in a table helps to build relationships with other tables.
👉Most relational databases support Structured Query Language (SQL).
👉Commonly used in ecommerce systems.
👉Also used in Online Transaction Processing (OLTP) such as Banking applications and Online retail applications.
Explore relational data structures
👉Relational database contains some other structures that help to optimize data organization.
- Helps to search data in a table.
- Indexes consume additional storage space.
- Some relational database management systems also support clustered indexes. A clustered index physically reorganizes a table by the index key.
- A table can have multiple indexes, but only a single clustered index.
- A virtual table based on the result set of a query.
Choose the right platform for a relational workload
👉On-premise database hosting is expensive.
👉All tasks including including scaling, patching, updating and maintaining security should be handle by the organization which is a trivial task.
👉Cloud consists of two different models to host databases.
- Database is hosted on a virtual machine.
- OS level control is provided over the system.
- All tasks such are patching and updating software should be handle by the organization.
- The cloud provider handles hardware maintenance and software maintenance.
- Can easily scale the database based on demand.
- Ex: Azure SQL Database, Azure Database for PostgreSQL, Azure Database for MySQL, and Azure Database for MariaDB
- Some database features are missing from the respective database type due to security concerns.