-- *** before: ***
-- clearing a table was a DELETE that logged every row
DELETE FROM city_import

-- *** in version 2008: ***
TRUNCATE TABLE city_import

-- Support: MySQL, PostgreSQL, Oracle and MS SQL Server. PostgreSQL can
-- truncate several tables at once and add CASCADE; in Oracle and MySQL
-- the statement commits the transaction. SQLite, Firebird and Access
-- have no TRUNCATE - DELETE FROM is the only way, and SQLite turns a
-- DELETE without WHERE into the fast path itself.