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Intersect

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Intersect

Don’t start Intersect with jargon. Start with a Intersect dry-run. That is the whole point.

Keep Intersect small. Arun should finish a Intersect dry-run in a few lines, not a 40-line dump.

Without Intersect, a viva board gets messy and a Intersect dry-run is hard to trust.

Use Intersect when a Intersect dry-run must stay clear. If a simpler SQL step works, use that instead.

Intersect trap — skipping the failure case for Intersect. Arun loses marks for that every viva.

Place Intersect next to nearby SQL work — one Intersect step Arun can write from memory is the link.

Close Intersect with: “If I skip it, a Intersect dry-run goes wrong like this: skipping the failure case for Intersect.”

Exam tip

For Intersect: definition + a viva board + one failure.

Intersect — sample query

-- Intersect
CREATE TABLE demo (
  id INTEGER PRIMARY KEY,
  label TEXT NOT NULL,
  qty INTEGER DEFAULT 0
);
INSERT INTO demo (id, label, qty) VALUES
  (1, 'alpha', 2),
  (2, 'beta', 5);
SELECT label, qty FROM demo WHERE qty >= 2 ORDER BY qty DESC;

Intersect: create two demo rows, then SELECT qty >= 2 ordered. Say which labels come back.

Short notes

DefIntersect — Arun uses it for a Intersect dry-run in a viva board.
RuleIntersect → one Intersect step Arun can write from memory.
RememberIntersect + an index (a viva board).
UseIntersect in a viva board (a Intersect dry-run).
TrapIntersect — skipping the failure case for Intersect.
ExIntersect → a Intersect dry-run.

-- Intersect CREATE TABLE demo ( id INTEGER PRIMARY KEY, label TEXT NOT NULL, qty INTEGER DEFAULT 0 ); INSERT INTO demo (id, label, qty) VALUES (1, 'alpha', 2), (2, 'beta', 5); SELECT label, qty FROM demo WHERE qty >= 2 ORDER BY qty DESC;

Intersect

Intersect — sample query

Short notes

Questions

Intersect

Intersect — sample query

Short notes

Questions