Minimizing Down Time Forums - Powered by vBulletin
Results 1 to 2 of 2

Thread: Minimizing Down Time

  1. #1
    Join Date
    Jun 2000
    chennai,tamil nadu,india

    Minimizing Down Time

    We have a DB with more than 5 terra.Right now we have maintennce every week for 5 Hours.During this hours we normally do changes to schemas(such as rebuilding indexes adding columns to some application tables etc).Now our customer wants to reduce the down time to 0 for this kind of changes.Let me know what is the best practice to make the changes to schemas without affecting the onlines and 0 down time.

    Some of you guys might have the db 24/7.How you do the changes without affecting onlines???.

    We tried redef package/rebuild online but all this take more time to sync the database.

    We do have standby's for the production db's.


  2. #2
    Join Date
    May 2000
    Most of ONLINE commands as described in Oracle documentation (good for learning) may not be workable in real life production environment.

    I believe still You need a maintenance window.

    For example:

    10:31:50 SQL> create table t1 (id int);

    Table created.

    Elapsed: 00:00:00.01
    10:31:57 SQL> insert into t1 values (10);

    1 row created.

    Elapsed: 00:00:00.00
    10:32:05 SQL>

    In another window, I tried this:

    10:32:18 SQL> alter table t1 add (c2 int) ;
    alter table t1 add (c2 int)
    ERROR at line 1:
    ORA-00054: resource busy and acquire with NOWAIT specified

    And if you want to use DBMS_REDEFINITION, then you need twice the space of the table.

    What you have to do is:
    Speed up your work in production.
    Test your script in a test environment before you execute it prod.
    Instead of rebuilding indexes, do coalesce.
    Change weekly maintenance to Monthly maintenance.
    There are plenty of ways.........


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts

Click Here to Expand Forum to Full Width