Defining a MAXVALUE partition v15

A MAXVALUE partition or subpartition captures any rows that don't fit into any other partition in a range-partitioned or subpartitioned table. If you don't include a MAXVALUE rule, any row that exceeds the maximum limit specified by the partitioning rules causes in an error. Each partition or subpartition can have its own MAXVALUE partition.

The syntax of a MAXVALUE rule is:

PARTITION [<partition_name>] VALUES LESS THAN (MAXVALUE)

Where partition_name specifies the name of the partition that stores any rows that don't match the rules specified for other partitions.

This example created a range-partitioned table in which the data was partitioned based on the value of the date column. If you attempt to add a row with a date value that exceeds a date listed in the partitioning constraints, EDB Postgres Advanced Server reports an error.

edb=# INSERT INTO sales VALUES
edb-#   (40, '3000x', 'IRELAND', '01-Mar-2013', '45000');
ERROR:  no partition of relation "sales" found for row
DETAIL:  Partition key of the failing row contains (date) = (01-MAR-13 00:00:00).

This CREATE TABLE command creates the same table but with a MAXVALUE partition. Instead of throwing an error, the server stores any rows that don't match the previous partitioning constraints in the others partition.

CREATE TABLE sales
(
  dept_no     number,
  part_no     varchar2,
  country     varchar2(20),
  date        date,
  amount      number
)
PARTITION BY RANGE(date)
(
  PARTITION q1_2012 VALUES LESS THAN('2012-Apr-01'),
  PARTITION q2_2012 VALUES LESS THAN('2012-Jul-01'),
  PARTITION q3_2012 VALUES LESS THAN('2012-Oct-01'),
  PARTITION q4_2012 VALUES LESS THAN('2013-Jan-01'),
  PARTITION others VALUES LESS THAN (MAXVALUE)
);

To test the MAXVALUE partition, add a row with a value in the date column that exceeds the last date value listed in a partitioning rule. The server stores the row in the others partition.

INSERT INTO sales VALUES
  (40, '3000x', 'IRELAND', '01-Mar-2013', '45000');

Query the contents of the sales table to confirm that the previously rejected row is now stored in the sales_others partition:

edb=# SELECT tableoid::regclass, * FROM sales;

   tableoid    | dept_no | part_no | country  |        date        | amount
---------------+---------+---------+----------+--------------------+--------
 sales_q1_2012 |      10 | 4519b   | FRANCE   | 17-JAN-12 00:00:00 |  45000
 sales_q1_2012 |      20 | 3788a   | INDIA    | 01-MAR-12 00:00:00 |  75000
 sales_q1_2012 |      30 | 9519b   | CANADA   | 01-FEB-12 00:00:00 |  75000
 sales_q2_2012 |      40 | 9519b   | US       | 12-APR-12 00:00:00 | 145000
 sales_q2_2012 |      20 | 3788a   | PAKISTAN | 04-JUN-12 00:00:00 |  37500
 sales_q2_2012 |      30 | 4519b   | CANADA   | 08-APR-12 00:00:00 | 120000
 sales_q2_2012 |      40 | 3788a   | US       | 12-MAY-12 00:00:00 |   4950
 sales_q3_2012 |      10 | 9519b   | ITALY    | 07-JUL-12 00:00:00 |  15000
 sales_q3_2012 |      10 | 9519a   | FRANCE   | 18-AUG-12 00:00:00 | 650000
 sales_q3_2012 |      10 | 9519b   | FRANCE   | 18-AUG-12 00:00:00 | 650000
 sales_q3_2012 |      20 | 3788b   | INDIA    | 21-SEP-12 00:00:00 |   5090
 sales_q3_2012 |      40 | 4788a   | US       | 23-SEP-12 00:00:00 |   4950
 sales_q4_2012 |      40 | 4577b   | US       | 11-NOV-12 00:00:00 |  25000
 sales_q4_2012 |      30 | 7588b   | CANADA   | 14-DEC-12 00:00:00 |  50000
 sales_q4_2012 |      40 | 4788b   | US       | 09-OCT-12 00:00:00 |  15000
 sales_q4_2012 |      20 | 4519a   | INDIA    | 18-OCT-12 00:00:00 | 650000
 sales_q4_2012 |      20 | 4519b   | INDIA    | 02-DEC-12 00:00:00 |   5090
 sales_others  |      40 | 3000x   | IRELAND  | 01-MAR-13 00:00:00 |  45000
(18 rows)

EDB Postgres Advanced Server doesn't have a way to reassign the contents of a MAXVALUE partition or subpartition.

• You can't use the ALTER TABLE… ADD PARTITION statement to add a partition to a table with a MAXVALUE rule. However, you can use the ALTER TABLE… SPLIT PARTITION statement to split an existing partition.
• You can't use the ALTER TABLE… ADD SUBPARTITION statement to add a subpartition to a table with a MAXVALUE rule. However, you can split an existing subpartition with the ALTER TABLE… SPLIT SUBPARTITION statement.