Does dropping a MySQL table automatically drop that table's indices too? [duplicate]

Question

Does dropping a MySQL table automatically drop that table's indices too?

Answer 1

Yes. It drops the indexes. This can be verified:

CREATE TABLE table1 (foo INT);
CREATE INDEX ix_table1_foo ON table1 (foo);
CREATE INDEX ix_table1_foo ON table1 (foo); -- fails: index already exists.
DROP TABLE table1;
CREATE TABLE table1 (foo INT);
CREATE INDEX ix_table1_foo ON table1 (foo); -- succeeds: index does not exist.

You can also verify it by looking in the information schema:

CREATE TABLE table1 (foo INT);
CREATE INDEX ix_table1_foo ON table1 (foo);

SELECT COUNT(*)
FROM information_schema.STATISTICS
WHERE INDEX_NAME = 'ix_table1_foo';  -- returns 1

DROP TABLE table1;

SELECT COUNT(*)
FROM information_schema.STATISTICS
WHERE INDEX_NAME = 'ix_table1_foo';  -- returns 0

Answer 2

Yes. Indices are part of their owner table and are freed along with the row data when dropped.

(Foreign-key indices on other tables that refer to it will prevent the table being dropped.)