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Compare GROUP BY 、CUBE 、ROLLUP

CREATE TABLE DEPART (dept char(10),
employee char(6)…


SELECT * FROM table_a
UNION/UNION ALL
SELECT * FROM table_b

Dirty read

Transaction B is rolled back at this time, then the second transaction A reads dirty data which age is 18

Phantom read






Green means the MySQL Server is running
/usr/local/mysql/support-files/mysql.server stop

Jenny

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