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Home -> Community -> Usenet -> c.d.o.server -> Re: What is the different between incremental and cumulative export ?
> On Tue, 11 Jan 2000 06:18:09 GMT, yewpc_at_rnd.celcom.com.my wrote:
>
> >Can anyone tell me what is the different between incremental and
> >cumulative backup ?
Alex Hudghton wrote:
>
> I'd guess at :
>
> Incremental - saves all files changed since the last backup
>
> Cumulative - saves all files changed since the last FULL backup
Files?
Instead of guessing at answers, how about looking at the documentation?
Note that exports are a very bad way to perform backup. Oracle
encourages the use of physical backups for purposes of recovery. See the
Oracle8 Backup and Recovery Guide. A system restored from an export
cannot be recovered to a point in time using redologs. Also, restoring
from an export takes more time and is more complex than restoring a
physical backup.
--
Jeremiah
From Oracle8 Utilities Guide Release 8.0
If you use cumulative and incremental Exports, you should periodically perform a complete Export to create a base backup. Following the complete Export, perform frequent incremental Exports and occasional cumulative Exports. After a given period of time, you should begin the cycle again with another complete Export.
Incremental Exports
An incremental Export backs up only tables that have changed since the last incremental, cumulative, or complete Export. An incremental Export exports the table definition and all its data, not just the changed rows. Typically, you perform incremental Exports more often than cumulative or complete Exports.
Cumulative Exports
A cumulative Export backs up tables that have changed since the last cumulative or complete Export. A cumulative Export compresses a number of incremental Exports into a single cumulative export file. It is not necessary to save incremental export files taken before a cumulative export because the cumulative export file replaces them.
Complete Exports
A complete Export establishes a base for incremental and cumulative Exports. It is equivalent to a full database Export, except that it also updates the tables that track incremental and cumulative Exports. Received on Tue Jan 11 2000 - 10:50:32 CST
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