gistfile1.txt

mysql> BEGIN;
Query OK, 0 rows affected (0.00 sec)

mysql> CREATE TABLE a (a text);
Query OK, 0 rows affected (0.00 sec)

mysql> ROLLBACK;
Query OK, 0 rows affected (0.00 sec)

mysql> describe a;
+-------+------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+------+------+-----+---------+-------+
| a     | text | YES  |     | NULL    |       | 
+-------+------+------+-----+---------+-------+
1 row in set (0.00 sec)


VS


testing=# BEGIN;
BEGIN
testing=# CREATE TABLE a (a text);
CREATE TABLE
testing=# ROLLBACK;
ROLLBACK
testing=# \d a
Did not find any relation named "a".