Question

I have a table with an indexed varchar(256) column.

For faster bulk insert, I disabled keys, insert more than 10 million entries, and then re-enable the keys after insertion is done.

Surprisingly, the enable/disable keys took no time:

mysql> alter table xxx disable keys;
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> alter table xxx enable keys;
Query OK, 0 rows affected, 1 warning (0.00 sec)

How do I ensure that enable/disable keys were working properly?

Answer 1

As you guessed, InnoDB does not support DISABLE/ENABLE KEYS. The warning you got is:

code 1031 – Table storage engine for
‘table_name’ doesn’t have this option

As you can see here.
To see the warning yourself, run SHOW WARNINGS; after you run the ALTER.