Prev | Current Page 844 | Next

Richard Niemiec

"Oracle Database 10g Performance Tuning Tips & Techniques"

In the partition clause, you can specify the overflow clause as well
as any other attributes of the overflow segment specific to a partition.
As of Oracle 10g, there is no longer the restriction that the set of partitioning columns must be
a subset of the IOT??™s primary key columns; in addition, LIST partitioning is supported in addition
to range and hash partitioning. In previous releases of Oracle, LOB columns were supported
only in range-partitioned IOTs; as of Oracle 10g, they are supported in hash and list partitioning
methods as well.
Managing Partitions
Fourteen maintenance operations can be performed on a partitioned table, including splitting a
partition, merging partitions, and adding a new partition. These operations may or may not be
available depending on the partitioning scheme used (range, hash, list, or one of the six composite
methods). For composite partitions, these operations sometimes apply to both the partition and
the subpartition, and sometimes to the subpartition only.
For partitioned indexes, there are seven different types of maintenance operations that vary
depending on both the partitioning method (range, hash, list, or composite) as well as whether
the index is a global or a local index. In addition, each type of partitioned index may support
automatic updates when the partitioning scheme is changed, thus reducing the occurrences of
unusable indexes.
In the next couple sections, I??™ll present a convenient chart for both partitioned tables and
partitioned indexes that shows you what kinds of operations are allowed on which partition types.


Pages:
832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856
Wzory Umów hotelarstwo agencja reklamowa wrocław Pióra Wieczne poker online