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Measures reported by OraExtentsTest
An extent in Oracle is a set of
contiguous blocks allocated in Oracle for storage of data. Since this is one of
the basic units of allocation, proper management of extents is essential for
efficient database performance. The OraExtentsTest helps in identifying objects
that are running out of extents and those that are using too many extents.
Note:
This test is applicable only for Oracle databases with ‘Dictionary Managed Tablespace’. From Oracle 9i onwards, all tablespaces are ‘Locally Managed Tablespaces’. Therefore, this test is applicable only upto Oracle 8i.
| Measurement |
Description |
Measurement
Unit |
Interpretation |
| Cannot_extend_objects
|
This measure
indicates the number of objects that cannot extend any further by
acquiring new extents. |
Number
|
This measure indicates the objects have run out of extents. This could
be because the objects are either too fragmented or the number of
extents allocated to them are too less. Consider modifying the
“maxextents” parameter to rectify this. Alternately if
fragmentation is the cause then, Consider exporting and then dropping
and re-importing the object.
The detailed diagnosis of this measure, if available, provides a
complete list of objects that cannot be extended.
|
| Large_extent_objects
|
This measure
indicates the object that exceeds a pre-specified number of extents.
The threshold value for the number of extents is configured via the
admin user interface. |
Number
|
This indicates that
the objects are using up more extents than the threshold set. This
over-utilization can be due to different types of fragmentation.
Consider exporting and then dropping and re-importing the object. Note
that the storage parameters set also affects how the extents are
allocated.
|
Note:
Objects in tablespaces that have atleast one datafile enabled for autoextension will be excluded by this test.
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