Automatic storage table spaces

With automatic storage table spaces, storage is managed automatically. The database manager creates and extends containers as needed.

Any table spaces that you create are managed as automatic storage table spaces unless you specify otherwise or the database was created using the AUTOMATIC STORAGE NO clause. With automatic storage table spaces, you are not required to provide container definitions; the database manager looks after creating and extending containers to make use of the storage allocated to the database. If you add storage to a storage group, new containers are automatically created when the existing containers reach their maximum capacity. If you want to make use of the newly-added storage immediately, you can rebalance the table space, reallocating the data across the new, expanded set of containers and stripe sets. Or, if you are less concerned about I/O parallelism, and just want to add capacity to your table space, you can forego rebalancing; in this case, as new storage is required, new stripe sets will be created.

Automatic storage table spaces can be created in a database using the CREATE TABLESPACE statement. By default, new tables spaces in a database are automatic storage table spaces, so the MANAGED BY AUTOMATIC STORAGE clause is optional. You can also specify options when creating the automatic storage table space, such as its initial size, the amount that the table space size will be increased when the table space is full, the maximum size that the table space can grow to, and the storage group it uses. Following are some examples of statements that create automatic storage table spaces:

CREATE TABLESPACE TS1
CREATE TABLESPACE TS2 MANAGED BY AUTOMATIC STORAGE
CREATE TEMPORARY TABLESPACE TEMPTS
CREATE USER TEMPORARY TABLESPACE USRTMP MANAGED BY AUTOMATIC STORAGE
CREATE LARGE TABLESPACE LONGTS
CREATE TABLESPACE TS3 INITIALSIZE 8K INCREASESIZE 20 PERCENT MANAGED BY AUTOMATIC STORAGE
CREATE TABLESPACE TS4 MAXSIZE 2G 
CREATE TABLESPACE TS5 USING STOGROUP SG_HOT 

Each of these examples assumes that the database for which these table spaces are being created has one or more defined storage groups. When you create a table space in a database that has no storage groups defined, you cannot use the MANAGED BY AUTOMATIC STORAGE clause; you must create a storage group, then try again to create your automatic storage table space.