Creating an Index Online - 線上建立索引

http://www.itpub.net/showthread.php?threadid=336222&pagenumber=   

線上建立INDEX的文章 。

 

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Creating an Index Online
Previously, when creating an index on a table there has always been a DML S-lock on that table during the index build operation, which meant you could not perform. DML operations on the base table during the build.

Now, with the ever-increasing size of tables and necessity for continuous operations, you can create and rebuild indexes online--meaning you can update base tables at the same time you are building or rebuilding indexes on that table. Note, though, that there are still DML SS-locks, which means you cannot perform. other DDL operations during an online index build.

The following statements perform. online index build operations:

ALTER INDEX emp_name REBUILD ONLINE;

CREATE INDEX emp_name ON emp (mgr, emp1, emp2, emp3) ONLINE;

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Note:
While you can perform. DML operations during an online index build, Oracle recommends that you do not perform. major/large DML operations during this procedure. For example, if you wish to load rows that total up to 30% of the size of an existing table, you should perform. this load before the online index build.

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When the ONLINE keyword is specified as a part of an ALTER INDEX or CREATE INDEX command, a temporary index-organized journal table is created to record changes made to the base table. This journal table is created in the same tablespace as the index being altered or created.
While the server process is rebuilding the index, other users can continue to access the old index structure. Any updates to the old index during the rebuild operation are recorded in the journal table.

所謂的journal table 就是:
ORA-08120: Need to create SYS.IND_ONLINE table in order to (re)build index
Cause: Alter index Build/Rebuild online require existing of SYS.IND_ONLINE table.
Action: User/DBA needs to create sys.ind_online before alter the index /rdbms/admin/catcio.sql contains script. to create ind_online.

 

Online Index Rebuild (continued) 

When the server process has completed the rebuild operation, it merges the changes entered
in the journal. This merge by which changed rows are incorporated into the new index is
done while the table is still online.
This is accomplished by scanning the journal table and operating on a per row basis.
Operations are committed every 20 rows. Locked rows are skipped. The Oracle server
process may make multiple passes over the journal table to process previously locked rows.

 

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主題: Ora-8120 On Online Index Rebuild After 9.2.0.5 Upgrade
型別: PROBLEM
狀態: MODERATED
內容型別: TEXT/X-HTML
建立日期: 31-MAR-2004
上次修訂日期: 12-MAY-2004

The information in this article applies to:
Oracle Server - Enterprise Edition - Version: 9.2.0.5
This problem can occur on any platform.

Errors
ORA-8120
RFA-1304

Symptoms
You have applied the 9205 patchset and when you try to rebuild an index online, you receive the following error:

ORA-08120: Need to create SYS.IND_ONLINE$ table in order to (re)build index
Changes
A new table, SYS.IND_ONLINE$, was created in the 9205 patchset that is referenced to relieve the performance related issues that are caused when rebuilding an index online. When rebuilding an index online, this table is updated, however, this table does not exist in the dictionary for 9205. Please note that this is NEW to 9205
Fix
Log into the database as the SYSDBA user and run the following script. from ORACLE_HOME/rdbms/admin

% @catcio.sql

References

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catcio.sql中的內容如下:
SET ECHO ON
SET FEEDBACK 1
SET NUMWIDTH 10
SET LINESIZE 80
SET TRIMSPOOL ON
SET TAB OFF
SET PAGESIZE 100

create table ind_online$
( obj# number not null,
type# number not null, /* what kind of index is this? */
/* normal : 1 */
/* bitmap : 2 */
/* cluster : 3 */
/* iot - top : 4 */
/* iot - nested : 5 */
/* secondary : 6 */
/* ansi : 7 */
/* lob : 8 */
/* cooperative index method : 9 */
flags number not null
/* index is being online built : 0x100 */
/* index is being online rebuilt : 0x200 */
)
/

實際上是在Oracle建庫時,沒有呼叫catcio.sql,也可算是個BUG吧.自已手動建立一下此表就行了.