DBMS - CMU DB user group

July 30,2022

last update: 2024-11-19

Sources

• CMU database group

Relational model

Relation is unordered set of tuples. A tuple is a set of attribute values.

Primary Keys

Synthetic Ids created to identify a tuple. Some dbs autogenerate these keys.

Foreign Keys:

Defines mapping between two tables.

Data manipulation Language (DML)

• Procedural
  • The query specifies the strategy to fetch the data.
• Non-Procedural
  • The query only specifies only what data is wanted and not how to find it.