Try it — one click
loading engine…Every button runs a real query. Watch the right side light up, then read “What just happened?” below.
Results
Click a button above to see results here.
The strategy — the engine explains how it decided to search
Before running anything, the engine picks a strategy — shortcut or full search — and explains it here.
Write your own — for the SQL-curious
Shelves it visited — each square is one “shelf” (page) of records
fetched a shelf
already in hand
updated a shelf
safety diary
A play-by-play of everything the engine touches appears here as it happens.
The signs
how it finds one record without reading them all — shelves visited by the last query glowThe tree appears once a table exists.
How to read this page
- The grid of squares is the database file: every square is a “shelf” holding a chunk of records. Watch which ones light up — that's exactly how much work your question caused.
- The tree works like signs in a library: start at the top, follow two or three arrows, land on the one right shelf. That's why finding ID #250 touches 2 shelves while searching by age checks all of them.
- The purple lines are the safety diary: every change is written there first and saved to disk before the real records are touched. If the power died mid-save, the diary is replayed on restart — finished saves survive, half-finished ones vanish. Nothing is ever left corrupted.
- The strategy panel is the engine thinking out loud: “I have a shortcut for this” vs. “I'll have to check everything.”