You want to empty a large table of all its rows quickly while keeping the table structure for reuse, without row-by-row processing. Which command is designed for this?
Correct answer D. TRUNCATE TABLE t;
Explanation
TRUNCATE removes all rows at once by deallocating the table's storage instead of scanning and deleting each row, so it is much faster on large tables and accepts no WHERE clause. DELETE without WHERE also empties the table but processes rows one by one and fires row-level delete triggers. DROP TABLE removes the table definition itself, so the structure is lost. ALTER TABLE ... DROP ROWS is not valid SQL.
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