Oracle provides a number of built-in packages to help the busy DBA manage space and diagnose
problems. For example, Oracle Segment Advisor, introduced in Oracle Database 10g, helps to
determine if a database object has space available for reuse, given how much fragmentation exists
in the object. Other features of Oracle, such as Resumable Space Allocation, allow a long-running
operation that runs out of disk space to be suspended until the DBA can intervene and allocate
enough additional disk space to complete the operation. As a result, the long-running job will
not have to be restarted from the beginning.
We??™ll also cover some of the key data dictionary and dynamic performance views that give
us a close look at the structure of the database and a way to optimize space usage. Many of the
scripts provided in this chapter use these views.
At the end of this chapter, we??™ll cover two different methods for automating some of the scripts
and Oracle tools: using the DBMS_SCHEDULER built-in package as well as using the Oracle
Enterprise Manager (OEM) infrastructure.
Space usage for tablespaces will be the primary focus in this chapter, along with the objects
contained within the tablespaces. Other database files, such as control files and redo log files, take
up disk space, but as a percentage of the total space used by a database they are small. We will,
however, briefly consider how archived log files are managed because the number of archived log
files will increase indefinitely at a pace proportional to how much DML activity occurs in the
database.
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