Reports cases when you try to drop columns from indexed tables. This inspection is available in Microsoft SQL Server and Sybase ASE.

Example (Microsoft SQL Server):

CREATE TABLE test_index
(
col  INT NOT NULL,
col2 INT NOT NULL,
col3 INT NOT NULL UNIQUE,
col4 VARCHAR(200)
);

CREATE UNIQUE INDEX aaaa ON test_index (col, col2);

ALTER TABLE test_index
DROP COLUMN col;

You cannot delete the col column because it is in the indexed table. To delete the column, you need to delete the aaaa index first (for example, DROP INDEX aaaa).