Lesson 05 · 12 min
Changing data, transactions, indexes
INSERT, UPDATE, DELETE, carefully. A transaction is all or nothing.
INSERT adds rows, UPDATE changes them, DELETE removes them. RETURNING gives back the changed rows without a separate SELECT. A transaction (BEGIN … COMMIT) groups several changes: all of them apply or none. An index speeds up lookups by a column, like the alphabetical index in a book.
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