Logical Primary Key

In relational database terms, a "logical primary key" refers to a column or combination of columns in a database table that is designated as the unique identifier for each row or record in that table. The primary key serves as a reference point for establishing relationships between different tables in a relational database.

The logical primary key is a conceptual designation rather than a physical attribute. It represents the logical or conceptual uniqueness of a record and is typically implemented using a unique constraint or index in the database.

By enforcing uniqueness, the primary key ensures that each row in the table can be uniquely identified and accessed. It provides a means to uniquely identify and relate records across different tables through foreign key relationships, enabling efficient data retrieval and maintaining data integrity.

In most cases, a logical primary key consists of a single column, often an auto-incrementing numeric value. However, it can also be composed of multiple columns if the combination of those columns guarantees uniqueness across the table.