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FIGURE 9-2. Partitioning using Oracle Database 10g partitioning
The size of each underlying data file is generally smaller for partitioned tables than nonpartitioned tables. This allows for easier and quicker backups.
Historical partitions can be made read-only and will not need to be backed up more than once. This also means faster backups.
The structure of a partitioned table needs to be defined only once. As new subsets of data are acquired, they will be assigned to the correct partition, based on the partition option chosen.
Individual tablespaces and/or their data files can be taken offline for maintenance or archiving without affecting access to other subsets of data. For example, assuming data for a table is partitioned by month (later in this chapter, we will discuss the different types of partitioning) and only 13 months of data is to be kept online at any one time, when a new month is acquired, the earliest month is archived and dropped from the table. This is accomplished using the command alter table abc drop partition xyz and does not affect access to the remaining 12 months of data.
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