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RMAN ISSUE

user_5667Jul 21 2013 — edited Jan 13 2015

Hi,

I am working with rman for the last couple of months. And i have some knowledge with this. As i am going to do some task in prod db, i have some confusing which i am going to ask here.

1.My db version is 11.1.0.7.0 and  COMPRESSION ALGORITHM 'BZIP2'. Can i use compress backup by issuing rman command like "backup as compressed backupset  format ..." ??

2.When I issued report obsolete, the output showed several controlfile copy and backup sets. If i delete obsolete , is there any chance that will delete any important file will cause the database a problem??

In one word..is delete obsolete is safe in any situation??

Regards,
This post has been answered by Asif Muhammad on Jul 21 2013
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Comments

Aman....
does existing user and new connection affect when we rebuild a index?

What kind of efect you are mentioning?
Aman....
Anand...
Hii..

let me try to answer your query, it might not be 100% correct.
When you rebuild the index using ONLINE clause then, the copy of the index is maintained which is modified and then replaces the old index and by the time the new one is rebuilt the older one is used by the users.Whereas, when you simply do , alter index indexname rebuild; the index goes into unusable state and will not be available to the users.If the index which is going to be rebuilt is already being used by someone then you will get ORA error sayin RESOURCE BUSY WAIT...

Anand
26741
1. A REBUILD locks the table (the table can still be queried). A REBUILD ONLINE allows operations to run concurrently against the table.

2. You run the risk of ORA-01410 errors. For a good explanation see http://jonathanlewis.wordpress.com/2007/09/16/index-rebuild/

3. In 10g and above a REBUILD implicitly updates statistics on the Index. This can change execution plans as Oracle parses SQL statements that execute after the REBUILD.

But, generically, existing user connections and user queries are NOT affected by a rebuild.


Hemant K Chitale
http://hemantoracledba.blogspot.com
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