Paths/Data Engineer/SQL & Query Craft / Indexes & Query Plans
Read a Query Plan
The plan tells you what the database did. Read one, find the expensive step and write down what you will change.
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01Requirements
live checks- File ~/warehouse/plan.md exists○
- The document names the plan command and the scan types it showed○
- The document names the step that cost the most○
- The document states the change you will make○
02Walkthrough
1 of 4 revealed- 01
Write the heading
Start with the query and the plan command. EXPLAIN ANALYZE runs the query and shows the real timings.
echo '# Query plan review\n\n## The query\n\nEXPLAIN ANALYZE the daily revenue query on the orders table.' > ~/warehouse/plan.md - 3 locked · each failed submit reveals one
03Stuck?
0 of 3 revealedTake a hint without losing the lab — each one points at the thing to look at, not at the answer.
04AI Tutor
guides, never solvesTell me what you're stuck on — I'll nudge, not solve. Which requirement are you looking at?
04Notebook
saved locally in this browserlearner@lab — ubuntu:24.04
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