Home » RDBMS Server » Server Administration » Regarding Import and Export
Regarding Import and Export [message #59831] Sun, 28 December 2003 22:58 Go to next message
Haneef
Messages: 7
Registered: June 2003
Junior Member
Hi All,

There is one query regarding Import and Export.
I have last Export on 25th Dec 2003. On 26th evening my data gets crash. Now I want to recover the same from the last Export. I alredy done the Import from the 25th's export.From that I recovered the data till 25th evening. What abt the 26th's data. Can I recover the same by using the redo log/archive log(if my database is in Archive log Mode).
My question is after Import , can we apply the redo log/archive log(if my database is in Archive log Mode) for the complete recovery.

Please Reply.

Thanks in Advance

Haneef.
Re: Regarding Import and Export [message #59833 is a reply to message #59831] Sun, 28 December 2003 23:05 Go to previous messageGo to next message
Frank Naude
Messages: 4502
Registered: April 1998
Senior Member
Hi,

Sorry for the bad news - you cannot.

See the Backup/Recovery FAQ at http://www.orafaq.net/faqdbabr.htm#HOW

"One of the advantages of exports is that one can selectively re-import tables, however one cannot roll-forward from an restored export file."

Best regards.

Frank
Re: Regarding Import and Export [message #59834 is a reply to message #59833] Sun, 28 December 2003 23:19 Go to previous messageGo to next message
Haneef
Messages: 7
Registered: June 2003
Junior Member
hi frank..

thankx for the ans. but still i am cofused. what is the advantage of using export and import utility. If in backup strategy i am using export/import utility. then my backup is not secure, because i can't use archive log.
If i can't use that archive log's .. then what is the best time to use this utility.and can u guide me should i remove this process "Taking backup through export/import" or not?
Re: Regarding Import and Export [message #59835 is a reply to message #59834] Mon, 29 December 2003 00:00 Go to previous messageGo to next message
Frank Naude
Messages: 4502
Registered: April 1998
Senior Member
Hi,

Most serious sites use logical backups (import/export) and physical backups (e.g. when using RMAN) for maximum protection. Importing is handy as you can restore a single table, physical backups are great for rolling-forward if archived logs are available.

Read the Backup/ Recovery FAQ again, everything should be explained in there.

Best regards.

Frank
Re: Regarding Import and Export [message #59836 is a reply to message #59835] Mon, 29 December 2003 00:32 Go to previous messageGo to next message
Frank
Messages: 7880
Registered: March 2000
Senior Member
Hi Frank,

Hey can you pls tell me then is export important for the recovery purpose. Hey we are used to take export daily and only on friday there is offline backup. Now if my data get crashed on Thrusday then i have to import till wednesday... then what abt thrusday's data... can i recover the same if my database is in archive log mode.

Thanks
Haneef.
Re: Regarding Import and Export [message #59837 is a reply to message #59836] Mon, 29 December 2003 00:48 Go to previous messageGo to next message
sachin kumar gupta
Messages: 157
Registered: March 2003
Senior Member
Hi haneef,

exp/imp is very easy for backups & for cross platform db migration. For recovering the db in case of failure, I will suggest u to take the hot backup on daily basis. But never forget to mulitplex the online redo log files,archived log files & control file on separate disks.

U can use incremental methods via RMAN if ur db size is too big.

U can take cold backup on friday if ur db availability is not so crucial.

Regards,
Sachin K. Gupta
Re: Regarding Import and Export [message #59838 is a reply to message #59837] Mon, 29 December 2003 01:59 Go to previous messageGo to next message
Haneef
Messages: 7
Registered: June 2003
Junior Member
Thanks Sachin.
Re: Regarding Import and Export [message #60268 is a reply to message #59831] Wed, 28 January 2004 11:01 Go to previous messageGo to next message
CARLOS
Messages: 24
Registered: February 2000
Junior Member
This solution is kind of experimental.
Try getting the SQL commands stored in the Archive Log files. These can be extracted using the Log Miner. With each command you will find the corresponding timestamp.

So, in theory, if you restore your Export and then apply the SQL commands executed from that moment, in the same order as found in the Logs, you should be able to bring your DB to a specific point in time.

Then again, I might be wrong. Maybe this method has flaws.
icon7.gif  Re: Regarding Import and Export [message #211378 is a reply to message #59831] Thu, 28 December 2006 05:07 Go to previous messageGo to next message
hitbin_chauhan
Messages: 1
Registered: April 2005
Location: Ahmedabad
Junior Member
Hi Frank/Haneef,
That means imp/exp is more advantageous when we are migerating the data from one Database to another; not for backup and recovery purpose.

Regards,
hitesh
hitbin_chauhan@yahoo.com
9825000304/9825404999
Re: Regarding Import and Export [message #211392 is a reply to message #211378] Thu, 28 December 2006 06:32 Go to previous message
Mohammad Taj
Messages: 2412
Registered: September 2006
Location: Dubai, UAE
Senior Member

hi,
Two type of backup procedure.
1.physical backup
2.logical backup.

1. physical backup.
you are able to recover point in time.
complete recovery
incomplete recovery.


2.logical backup
you are not able to recover point in time.
complete recovery
incomplete recovery

1.physical backup.
for physical backup you can use
1.RMAN ( server managed backup)
2.User managed backup.

Note : database running one of the two modes.
1.Archive log
In archive log you are able to recovery point in time recovery.

2.No archive log
In no archive log you are not able to perform point in time recovery.
Through .arc files.

---------------------------------------------------
Logical Backup.
Original EXP OR IMP Prior to 10g.
Datapump EXPDP OR IMPDP Introduced in 10g.


Complete DB, Particular Tablespace, Particular Users.
On First Machine ---> Export ---->On another machine ---> Import

Particular any tables
On first Machine ---> export ---> On another Machine ---> Import
On One Schema -------Export ----> On another Schema ---> Import.

Always keep in mind "export or import" just a tools to transfer data one side to another side. it is not proper backup or recovery method.

regards
Taj
Previous Topic: Oracle different edition after upgrade
Next Topic: ORA-23375: feature is incompatible with database version
Goto Forum:
  


Current Time: Sat Dec 10 16:28:23 CST 2016

Total time taken to generate the page: 0.10896 seconds