Frequently asked questions

Four things: Generate (translate an English question into SQL with your schema in scope), Explain (turn a SQL query into plain English), Optimise (suggest up to three concrete improvements with reasoning), and Fix (correct a broken query and explain the root cause).

The AI assistant is powered by Groq. When you use the assistant, your question and the relevant database schema (table and column names) are sent to Groq's API to generate a response. Your actual data rows are never included unless you explicitly paste them into the prompt.

Your natural-language question and the schema context are sent to Groq to generate a response. Your exercise submissions and BYO database row-level data are not sent to any AI provider. See our Privacy Policy for full details.

Yes. The AI assistant is available in the lesson editor, the Playground, and the DBA tool. Context (schema, query, lesson) is automatically included so the suggestions are relevant to what you're working on.

Use the 'Forgot password' link on the sign-in page. We'll send a reset link to the email address on your account via Brevo (our transactional email provider). Check your spam folder if it doesn't arrive within a few minutes.

Email changes are not yet self-service. Email hello@schemaschool.dev from your current account email and we will update it manually.

Deletion is permanent and irreversible. All progress, streak, achievements, exercise history, and DBA chat sessions are removed. Your Lifetime Access entitlement is also removed — a refund is only possible within the 7-day refund window.

Email hello@schemaschool.dev or visit our Contact page. We're a small team and aim to reply within one business day.

We store your email, password hash, display name, lesson completions, exercise attempts, streak, feedback (if you submit any), and visitor analytics events (page, referer, user-agent, IP). We do not store your BYO connection strings on our servers — those stay in your browser's localStorage.

Yes. The "Danger Zone" in your Settings page permanently deletes your account, all progress, exercise history, and DBA chat sessions. To request deletion of specific records (e.g., feedback), email hello@schemaschool.dev.

No. BYO connection strings are stored only in your browser's localStorage. They are never transmitted to or persisted on Schema School's servers. If you paste a connection string for a one-off query it is used only for that single request and then discarded.

Two first-party cookies: a session cookie (HttpOnly, SameSite=Lax, Secure) that keeps you signed in, and ss_vid — a 1-year pseudonymous visitor ID used only for counting unique visitors in our own analytics. We use no advertising cookies or third-party tracking pixels.

Schema School is a structured, hands-on school for SQL. You learn PostgreSQL through 37 guided lessons, 70+ graded exercises, animated diagrams, an AI assistant, and a streak system that makes it easy to show up every day. Everything runs in your browser — no local setup required.

No. Schema School is entirely browser-based. Create a free account, and you get immediate access to a pre-loaded PostgreSQL sandbox. There is nothing to download or configure.

PostgreSQL 16. The entire curriculum — from your first SELECT to window functions, CTEs, indexes, and EXPLAIN ANALYZE — targets PostgreSQL. Most syntax also works on earlier Postgres versions (12+) and, with minor differences, on MySQL and MariaDB.

Anyone who wants to genuinely understand SQL: beginners learning their first SELECT, developers who want to get comfortable with joins and aggregates, and engineers levelling up on window functions, JSONB, indexes, and query plans.

A focused learner can finish Chapters 1–3 (the fundamentals) in a weekend. Going through all 37 lessons and 70+ exercises with real understanding typically takes 20–30 hours over a few weeks. The streak system makes it easy to make progress in short daily sessions.

When you submit your query it runs against the sandbox alongside the reference answer. Results are compared automatically. If your output is close but not quite right, you'll see a diff highlighting exactly where it diverges so you know what to fix.

Three layers of help are available. Each exercise has a hint ladder you can reveal one step at a time. You can run partial queries without submitting to inspect intermediate results. And the AI assistant can generate, explain, optimise, or fix SQL — available in lessons, the playground, and the DBA tool.

Yes. Your profile page shows your streak, total XP, mastery percentage per chapter, and all achievements unlocked. Your attempt history is stored so progress survives across devices and sessions.

Seven chapters take you from basics to advanced: SELECT fundamentals, filtering and sorting, aggregates and GROUP BY, all JOIN types, subqueries and CTEs, window functions, and a performance chapter covering indexes, EXPLAIN ANALYZE, and partitions. JSONB and array types are woven in.

Yes. Beyond the basics the curriculum covers window functions (RANK, LEAD, LAG, NTILE), recursive CTEs, lateral joins, EXPLAIN ANALYZE, index types (B-tree, GIN, partial), table partitioning, and JSONB querying. The diagrams section has 48+ animated visual explainers.

Yes. You can create a free account and access the first lessons and diagrams to get a feel for the platform. Full access to all 37 lessons, 70+ exercises, the AI assistant, the DBA tool, and all diagrams requires a Lifetime Access purchase.

Lifetime Access is a one-time payment that unlocks the complete Schema School curriculum — all current lessons, exercises, and diagrams — plus any content we add in the future. There is no recurring subscription or monthly fee.

Payments are processed by Razorpay, a PCI-compliant payment gateway. Your card or banking details are entered directly on Razorpay's secure checkout and never touch Schema School's servers. We receive only confirmation that the payment succeeded.

We offer a 7-day full refund if you are not satisfied and have completed fewer than 5 lessons. Email hello@schemaschool.dev with your purchase details. See our Refund Policy for full details.

Yes. Your account and progress are tied to your email address, not a device. Sign in on any browser and your streak, progress, and access are all there.