As a result, you must have adequate space to store two copies
of the index while the operation is taking place. You can use the alter index rebuild command to
change the storage characteristics and tablespace assignment for an index.
To rebuild the index online, use the rebuild online clause of the alter table command, as
shown in the following example:
alter index AUTH$NAME rebuild online;
Coalescing Indexes Online
You can coalesce an index to reclaim space within the index. When you coalesce an index, you
cannot move it to another tablespace (as you can with a rebuild). Coalescing does not require
storage space for multiple copies of the index, so it may be useful when you are attempting to
reorganize an index in a space-constrained environment.
To coalesce an index, use the coalesce clause of the alter index command. All index
coalesces are online operations. The following is a sample coalesce:
alter index AUTH$NAME coalesce;
Rebuilding Index-Organized Tables Online
You can use the alter table . . . move online command to rebuild an index-organized table online.
The overflow data segment, if present, is rebuilt if you specify the overflow keyword. For example,
if the BOOKSHELF table is an index-organized table, you can rebuild it online via the following
command:
alter table BOOKSHELF move online;
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Chapter 14: Miscellaneous High Availability Features 507
When using this command, you cannot perform parallel DML.
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