Explore indexes, JOINs, normalization, and transaction isolation with interactive examples.

1. SQL Execution Order

   Follow a SELECT query from FROM to LIMIT and see the table change at each logical processing step.

2. JOIN

   Follow how INNER, LEFT, RIGHT, and FULL OUTER JOIN combine rows from two tables.

3. Indexes and B+ Trees

   Compare B+ tree lookups with full table scans by counting the pages read.

4. Normalization

   Split an unnormalized table into 1NF, 2NF, and 3NF and observe update, insertion, and deletion anomalies.

5. Transactions and Isolation Levels

   See whether dirty reads, non-repeatable reads, and phantom reads occur under different isolation levels.