MeritKeep

Query performance basics

Reading an EXPLAIN plan, index usage, sargability, and the handful of rewrites that fix most slow analytical queries.

specialist~3hWe mark it against a checklist you can read first
The barWhat counts as knowing this

Read an EXPLAIN plan, name why a query is slow, and rewrite it to be faster

That sentence is the bar. It only counts once your work shows you can do it. Reading about it does not.
Prove itA check for this one skill

Up to 2 questions on this skill alone, marked against the bar beside this. It stops as soon as the answer is clear. No account, and your answers are not kept.

01 · Prerequisites

You'll need these first

02 · Also helpful

Helpful, but not required

Start on SQL & Data Analysis

Every skill above, ordered by what depends on what, with the projects above that as the evidence you actually did it. We work out where you already are first, so the path skips what you can do.

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