Practise · Real PostgreSQL
SQL lab
Use real SQL to complete a guided task in a temporary PostgreSQL database. Your lab is isolated from every other learner and is removed when you finish or when it expires.
Your goal
Compare a baseline and revised plan, identify the expensive operation, and show the returned result remains correct.
What to do
- Start your temporary database.
- Read the task and run SQL in the workspace.
- Check your work. The server will inspect the database state.
- When every task passes, continue to the assessment.
Managed PostgreSQL workspace
Real SQL lab
A support report searches case references with a function-wrapped predicate and now reads far more rows than it returns.
Your database is temporaryIt is private to this lab and deleted when you finish or it expires.
Goal
Use execution-plan evidence to remove an avoidable full scan while checking that the query result stays correct.
Start when you are ready. Creating your private database can take a few seconds. You do not need a Neon account.