In this scenario, even 80GB is not big enough for this tablespace, so we will let it autoextend
20GB at a time:
SQL> alter tablespace whs01 autoextend on next 20g;
Tablespace altered.
Notice in both cases that we do not need to refer to a datafile; there is only one datafile, and once
the tablespace is created, we no longer need to worry about the details of the underlying datafile
and how it is managed.
Bigfile tablespaces are intended for use with Automatic Storage Management, discussed in the
next section.
Automatic Storage Management
Using Automatic Storage Management (ASM) can significantly reduce the administrative overhead
of managing space in a database because a DBA need only specify an ASM disk group when
allocating space for a tablespace or other database object. Database files are automatically
distributed among all available disks in a disk group, and the distribution is automatically updated
whenever the disk configuration changes. For example, when a new disk volume is added to an
existing disk group in an ASM instance, all datafiles within the disk group are redistributed to use
the new disk volume. I introduced ASM in Chapter 4. In this section, I??™ll revisit some other key
ASM concepts from a storage management point of view and provide more examples.
Because ASM automatically places datafiles on multiple disks, performance of queries and
DML statements is improved because the I/O is spread out among several disks.
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