ALTER TABLE DROP COLUMN
Drops a column from an existing table.
Before the operation can proceed, any current transactions are committed,
regardless of the success or failure of the
DROP operation. Dropping a column
does not lock the table for reading and does not wait on any reads to finish.
Dropping columns will also attempt to remove files belonging to the column from all partitions, thus freeing up disk space immediately. If this is not immediately possible on Windows, the file remove operation is postponed until files are released by all threads. The logical drop column will succeed on Windows in presence of active readers.
DROP COLUMN with care, as QuestDB cannot recover data from dropped
The following example deletes the column called
comment from the table