SQLMentor
SQL Glossary
Clear, example-backed definitions of the SQL and relational-database terms you meet most often — from primary keys and joins to ACID, isolation levels, and window functions. Every entry links to a hands-on tutorial where you can practise the concept in the free SQL editor.
Keys & Constraints
- Candidate Key
- CHECK Constraint
- Composite Key
- Constraint
- Foreign Key
- Natural Key
- ON DELETE CASCADE
- Primary Key
- Referential Integrity
- Surrogate Key
- Unique Constraint
Performance
- Bitmap Index
- Clustered Index
- Composite Index
- Covering Index
- Execution Plan (EXPLAIN)
- Full-Text Index
- Index
- Query Optimizer
- ROWID
- Table Partitioning
Design
- Data Type
- Data Warehouse
- Database Replication
- Database Schema
- Database Sharding
- Denormalization
- Normalization
- OLAP (Online Analytical Processing)
- OLTP (Online Transaction Processing)
- Star Schema
Querying
- Aggregate Function
- CASE Expression
- COALESCE
- Common Table Expression (CTE)
- Correlated Subquery
- Cross Join
- Derived Table
- EXISTS
- GROUP BY
- HAVING
- Inner Join
- NULL
- Outer Join
- PIVOT
- RANK() / DENSE_RANK()
- Recursive CTE
- ROW_NUMBER()
- Self Join
- SQL JOIN
- Subquery
- UNION
- UPSERT / MERGE
- Window Function
Objects
Procedural
Reliability
- ACID
- Deadlock
- Dirty Read
- Isolation Level
- Lock
- MVCC
- Non-Repeatable Read
- Optimistic Locking
- Pessimistic Locking
- Phantom Read
- Transaction