Indexes

An index improves query performance by allowing the database engine to locate rows more efficiently.

Source data — Pattern 14: Database Design & Performance

All queries run against the shared employees table (see schema.sql). This pattern introduces performance optimization and transaction management. Topic 85 introduces an accounts table to demonstrate COMMIT and ROLLBACK using a money transfer transaction.

Indexes — source table 1

Indexes — source table 2

What it does

An index improves query performance by allowing the database engine to locate rows more efficiently.

Problem

Create an index to optimize employee email searches.

CREATE INDEX idx_employee_email
ON employees(email);

Result

Indexes — result 3

SQL · Pattern 14 — Database Design & Performance

Indexes

An index improves query performance by allowing the database engine to locate rows more efficiently.

Source data — Pattern 14: Database Design & Performance

All queries run against the shared employees table (see schema.sql). This pattern introduces performance optimization and transaction management. Topic 85 introduces an accounts table to demonstrate COMMIT and ROLLBACK using a money transfer transaction.

Indexes — source table 1

Indexes — source table 2

What it does

An index improves query performance by allowing the database engine to locate rows more efficiently.

Problem

Create an index to optimize employee email searches.

CREATE INDEX idx_employee_email
ON employees(email);

Result

Indexes — result 3