Query plans

Study the pattern

EXPLAIN QUERY PLAN helps inspect how SQLite accesses data. Predict the output before running the example.

EXPLAIN QUERY PLAN SELECT order_id,amount FROM orders WHERE customer_id=1;

Explain it from memory

What does today's SQL feature do, and when would you use it?

Prefix the SELECT with EXPLAIN QUERY PLAN.

Run SQL in your browser

Run the example, then modify one clause and predict how the result changes.

Prefix the SELECT with EXPLAIN QUERY PLAN.

Consolidate the skill

• Run and inspect the output.
• Change one part and predict the difference.
• Return later and rewrite the query from memory.