Therefore, a good plan for managing archived log files will help keep disk space usage
under control.
Common Space Management Problems
Space management problems generally fall into one of three categories: running out of space in a
regular tablespace, not having enough undo space for long-running queries that need a consistent
???before??? image of the tables, and insufficient space for temporary segments. Although we may still
have some fragmentation issues within a database object such as a table or index, locally managed
tablespaces solve the problem of tablespace fragmentation.
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Chapter 6: Monitoring Space Usage 165
I will address each of these three problem areas by using the techniques described in the
following sections.
Running Out of Free Space in a Tablespace
If a tablespace is not defined with the AUTOEXTEND attribute, then the total amount of space in
all the datafiles that compose the tablespace limits the amount of data that can be stored in the
tablespace. If the AUTOEXTEND attribute is defined, then one or more of the datafiles that compose
the tablespace will grow to accommodate the requests for new segments or the growth of existing
segments. Even with the AUTOEXTEND attribute, the amount of space in the tablespace is ultimately
limited by the amount of disk space on the physical disk drive or storage group.
The AUTOEXTEND attribute is the default if you don??™t specify the SIZE parameter in the
create tablespace command and you are using OMF, so you??™ll actually have to go out of your
way to prevent a datafile from autoextending.
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