Database Systems Lab

Parameters

B-Tree order: 3

Table size: 50K rows

Isolation level: RR

Database Systems Explorer – SQL, Joins & Transactions

Database systems are software platforms that store, organize, and retrieve structured data reliably for multiple concurrent users. While a database index is a specific optimization within a database, understanding the full database system means grasping the relational model, SQL query processing, transaction management, and concurrency control. This explorer lets you write and run SQL against a live schema, observe join execution plans, and simulate concurrent transactions to see how isolation levels prevent data anomalies.

What you can do in this simulation

Write SQL SELECT statements with WHERE, JOIN, and GROUP BY and see results instantly
Visualize nested-loop, hash, and merge join strategies on sample tables
Simulate concurrent transactions and observe how locks prevent dirty reads
Toggle transaction isolation levels and watch how phenomena like phantom reads appear or disappear
Inspect the entity-relationship diagram for the sample schema and trace foreign keys

Concepts covered

relational database · SQL · ACID transactions · join operations · concurrency control · normalization

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