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Databases Beginner

What is Primary Key?

A column or set of columns that uniquely identifies each row in a database table.

A primary key ensures every row in a table is unique and identifiable. It cannot contain NULL values and must be unique across all rows. Common choices include auto-incrementing integers (SERIAL) or UUIDs.

Primary keys are automatically indexed for fast lookups. Composite primary keys use multiple columns together. Primary keys are referenced by foreign keys in other tables to create relationships.

Related Terms

Row-Level Security (RLS)
A database feature that restricts which rows a user can access in a table based on security policies.
Prepared Statement
A pre-compiled SQL template that uses parameters instead of literal values, preventing SQL injection and improving performance.
Partitioning
A technique of dividing large database tables into smaller, more manageable segments while maintaining a single logical table.
Schema
The structure definition of a database including tables, columns, data types, relationships, indexes, and constraints.
Database Index Types
Different index structures (B-tree, Hash, GIN, GiST, BRIN) optimized for various query patterns and data types.
ETL (Extract, Transform, Load)
A data pipeline process that extracts data from sources, transforms it into a suitable format, and loads it into a destination system.
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