More than one nonfragmented table

You can combine two or more nonfragmented tables into a single fragmented table. The nonfragmented tables must have identical table structures and must be stored in separate dbspaces. To combine nonfragmented tables, use the ATTACH clause of the ALTER FRAGMENT statement.

For example, suppose that you have three nonfragmented tables, account1, account2, and account3, and that you store the tables in dbspaces dbspace1, dbspace2, and dbspace3, respectively. All three tables have identical structures, and you want to combine the three tables into one table that is fragmented by the expression on the common column acc_num.

You want rows with acc_num less than or equal to 1120 to be stored in dbspace1. Rows with acc_num greater than 1120 but less than or equal to 2000 are to be stored in dbspace2. Finally, rows with acc_num greater than 2000 are to be stored in dbspace3.

ALTER FRAGMENT ON TABLE tab1 ATTACH
   tab1 AS acc_num <= 1120,
   tab2 AS acc_num >  1120 and acc_num <= 2000,
   tab3 AS acc_num > 2000;

The result is a single table, tab1. The other tables, tab2 and tab3, were consumed and no longer exist.

For information about how to use the ATTACH and DETACH clauses of the ALTER FRAGMENT statement to improve performance, see your HCL OneDB™ Performance Guide.