A little two-part quiz. If you get the first one without peeking, you're worth your pay as a DBA. If you get the second one without peeking, you may tell your boss that some random guy on the Internet says you deserve a raise.
Start with a text file, 'test.txt', with these three lines:
Set up the test in MySQL:
DROP TABLE IF EXISTS t1;
CREATE TABLE t1 (id int primary key);
LOAD DATA INFILE 'test.txt' INTO TABLE t1;
This gives "
ERROR 1062 (23000): Duplicate entry '1' for key 'PRIMARY'", which is expected.
What's in the table?
Now, pretend you're setting up a slave, or there was a crash and you're recovering from binary logs:
mysqlbinlog bin.000001 | mysql
How many rows are in t1 now?