With partitioning, a virtual column can be used as any regular column. All partition methods are supported when using virtual columns, including interval partitioning and all different combinations of composite partitioning. A virtual column used as the partitioning column cannot use calls to a PL/SQL function.
Oracle Database SQL Language Reference for the syntax on how to create a virtual column
Example 4-20 shows the
sales table partitioned by range-range using a virtual column for the subpartitioning key. The virtual column calculates the total value of a sale by multiplying
As the example shows, row movement is also supported with virtual columns. If row movement is enabled, then a row migrates from one partition to another partition if the virtual column evaluates to a value that belongs to another partition.
Example 4-20 Creating a table with a virtual column for the subpartitioning key
CREATE TABLE sales ( prod_id NUMBER(6) NOT NULL , cust_id NUMBER NOT NULL , time_id DATE NOT NULL , channel_id CHAR(1) NOT NULL , promo_id NUMBER(6) NOT NULL , quantity_sold NUMBER(3) NOT NULL , amount_sold NUMBER(10,2) NOT NULL , total_amount AS (quantity_sold * amount_sold) ) PARTITION BY RANGE (time_id) INTERVAL (NUMTOYMINTERVAL(1,'MONTH')) SUBPARTITION BY RANGE(total_amount) SUBPARTITION TEMPLATE ( SUBPARTITION p_small VALUES LESS THAN (1000) , SUBPARTITION p_medium VALUES LESS THAN (5000) , SUBPARTITION p_large VALUES LESS THAN (10000) , SUBPARTITION p_extreme VALUES LESS THAN (MAXVALUE) ) (PARTITION sales_before_2007 VALUES LESS THAN (TO_DATE('01-JAN-2007','dd-MON-yyyy')) ) ENABLE ROW MOVEMENT PARALLEL NOLOGGING;