Repair Table — SQL Technical Interview Questions & Answers

Repair Table

Repair Table

  • REPAIR TABLE is mainly for MyISAM tables that got corrupted. InnoDB almost never wants REPAIR TABLE — you use dump/restore or innodb recovery settings instead.
  • If a teacher’s old lab uses MyISAM and SELECT crashes, they may show REPAIR TABLE t; Don’t make it your default InnoDB answer.
  • Trap: REPAIR TABLE on InnoDB and thinking it ‘optimises’ like OPTIMIZE TABLE.
  • On the example next to this theory: Repair Table: create two demo rows, then SELECT qty >= 2 ordered. Say which labels come back.

Technical Interview Tip: MyISAM: REPAIR TABLE. InnoDB: don’t; restore from backup.

Code Examples for Repair Table

Repair Table — sample query

-- Repair Table
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;

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

How to Explain Repair Table to an Interviewer

When is REPAIR TABLE used?

MyISAM corruption Not the InnoDB everyday tool