You can drop an existing table by the DROP statement. Multiple tables can be dropped by a single DROP statement. All rows of table are also dropped. If you use it together with the IF EXISTS statement, you can prevent errors from occurring and specify multiple tables in one statement.
DROP [ TABLE | CLASS ] [ IF EXISTS ] <table_specification_comma_list>
<single_table_spec> | ( <table_specification_comma_list> )
|[ ONLY ] table_name
| ALL table_name [ ( EXCEPT table_name, ... ) ]
DROP TABLE history ;
CREATE TABLE t (i INT);
-- DROP TABLE IF EXISTS
DROP TABLE IF EXISTS history, t;
2 command(s) successfully processed.
SELECT * FROM t;
In line 1, column 10, ERROR: Unknown class "t".