CREATE TABLE test(i TIMESTAMP TIME INDEX, j INTEGER NOT NULL);

Affected Rows: 0

INSERT INTO test VALUES (1, 1), (2, 2);

Affected Rows: 2

SELECT * FROM test;

+-------------------------+---+
| i                       | j |
+-------------------------+---+
| 1970-01-01T00:00:00.001 | 1 |
| 1970-01-01T00:00:00.002 | 2 |
+-------------------------+---+

ALTER TABLE test DROP COLUMN j;

Affected Rows: 0

INSERT INTO test VALUES (3);

Affected Rows: 1

SELECT * FROM test;

+-------------------------+
| i                       |
+-------------------------+
| 1970-01-01T00:00:00.001 |
| 1970-01-01T00:00:00.002 |
| 1970-01-01T00:00:00.003 |
+-------------------------+

DROP TABLE test;

Affected Rows: 0