TRUNCATE TABLE removes all rows from a table. The table definition is preserved after truncation. When you truncate a partitioned table, all its partitions and subpartitions are truncated as well.
Syntax
TRUNCATE TABLE table_name;Parameters
| Parameter | Description |
|---|---|
table_name | The name of the table to truncate. Optionally schema-qualified, for example, schema_name.table_name. |
Prerequisites
To truncate a table, you must be one of the following:
The owner of the partitioning root
A member of a group that owns the table
The schema owner
A database superuser
Example: empty a partitioned table
This example creates a list-partitioned sales table, inserts 17 rows, verifies the data, and then truncates the table.
Create the table:
CREATE TABLE sales
(
dept_no number,
part_no varchar2,
country varchar2(20),
date date,
amount number
)
PARTITION BY LIST(country)
(
PARTITION europe VALUES('FRANCE', 'ITALY'),
PARTITION asia VALUES('INDIA', 'PAKISTAN'),
PARTITION americas VALUES('US', 'CANADA')
);Insert rows:
INSERT INTO sales VALUES
(10, '4519b', 'FRANCE', '17-Jan-2012', '45000'),
(20, '3788a', 'INDIA', '01-Mar-2012', '75000'),
(40, '9519b', 'US', '12-Apr-2012', '145000'),
(20, '3788a', 'PAKISTAN', '04-Jun-2012', '37500'),
(40, '4577b', 'US', '11-Nov-2012', '25000'),
(30, '7588b', 'CANADA', '14-Dec-2012', '50000'),
(30, '9519b', 'CANADA', '01-Feb-2012', '75000'),
(30, '4519b', 'CANADA', '08-Apr-2012', '120000'),
(40, '3788a', 'US', '12-May-2012', '4950'),
(10, '9519b', 'ITALY', '07-Jul-2012', '15000'),
(10, '9519a', 'FRANCE', '18-Aug-2012', '650000'),
(10, '9519b', 'FRANCE', '18-Aug-2012', '650000'),
(20, '3788b', 'INDIA', '21-Sept-2012', '5090'),
(40, '4788a', 'US', '23-Sept-2012', '4950'),
(40, '4788b', 'US', '09-Oct-2012', '15000'),
(20, '4519a', 'INDIA', '18-Oct-2012', '650000'),
(20, '4519b', 'INDIA', '2-Dec-2012', '5090');Verify data is present (the tableoid::regclass expression shows which partition each row belongs to):
acctg=# SELECT tableoid::regclass, * FROM sales;
tableoid | dept_no | part_no | country | date | amount
---------------+---------+---------+----------+--------------------+--------
sales_europe | 10 | 4519b | FRANCE | 17-JAN-12 00:00:00 | 45000
sales_europe | 10 | 9519b | ITALY | 07-JUL-12 00:00:00 | 15000
sales_europe | 10 | 9519a | FRANCE | 18-AUG-12 00:00:00 | 650000
sales_europe | 10 | 9519b | FRANCE | 18-AUG-12 00:00:00 | 650000
sales_asia | 20 | 3788a | INDIA | 01-MAR-12 00:00:00 | 75000
sales_asia | 20 | 3788a | PAKISTAN | 04-JUN-12 00:00:00 | 37500
sales_asia | 20 | 3788b | INDIA | 21-SEP-12 00:00:00 | 5090
sales_asia | 20 | 4519a | INDIA | 18-OCT-12 00:00:00 | 650000
sales_asia | 20 | 4519b | INDIA | 02-DEC-12 00:00:00 | 5090
sales_americas| 40 | 9519b | US | 12-APR-12 00:00:00 | 145000
sales_americas| 40 | 4577b | US | 11-NOV-12 00:00:00 | 25000
sales_americas| 30 | 7588b | CANADA | 14-DEC-12 00:00:00 | 50000
sales_americas| 30 | 9519b | CANADA | 01-FEB-12 00:00:00 | 75000
sales_americas| 30 | 4519b | CANADA | 08-APR-12 00:00:00 | 120000
sales_americas| 40 | 3788a | US | 12-MAY-12 00:00:00 | 4950
sales_americas| 40 | 4788a | US | 23-SEP-12 00:00:00 | 4950
sales_americas| 40 | 4788b | US | 09-OCT-12 00:00:00 | 15000
(17 rows)Truncate the table:
TRUNCATE TABLE sales;Verify the table is empty (the schema is intact, all rows are gone):
acctg=# SELECT tableoid::regclass, * FROM sales;
tableoid | dept_no | part_no | country | date | amount
----------+---------+---------+---------+------+--------
(0 rows)