Hash Partitioning Tables
Hash partitioning is useful when there is no obvious range key, or range partitioning will cause uneven distribution of data. The number of partitions must be a power of 2 (2, 4, 8, 16...) and can be specified by the PARTITIONS...STORE IN clause:
CREATE TABLE invoices
(invoice_noNUMBER NOT NULL,
invoice_dateDATE NOT NULL,
commentsVARCHAR2(500))
PARTITION BY HASH (invoice_no)
PARTITIONS 4
STORE IN (users, users, users, users);
or specified individually:
CREATE TABLE invoices
(invoice_noNUMBER NOT NULL,
invoice_dateDATE NOT NULL,
commentsVARCHAR2(500))
PARTITION BY HASH (invoice_no)
(PARTITION [B]invoices_q1[/B] TABLESPACE users,
PARTITION invoices_q2 TABLESPACE users,
PARTITION invoices_q3 TABLESPACE users,
PARTITION invoices_q4 TABLESPACE users); |