misconcept in backup mode

[ams-jamali]

Does backup mode stops writing into datafile?and increase in log file generation relates to this concept.

Explanations pls Thanks.

[gopu_g]

When you place a tablespace in backup mode, the Oracle instance notes that a backup is being performed and internally compensates for it. As you know, it is impossible to make an authentic copy of a database file that is being written to. On receipt of the command to begin the backup, however, Oracle ceases to make direct changes to the database file. It uses a complex combination of rollback segments, buffers, redo logs, and archive logs to store the data until the end backup command is received and the database files are brought back in sync.
Gopu

[davey23uk]

When you place a tablespace in backup mode, the Oracle instance notes that a backup is being performed and internally compensates for it. As you know, it is impossible to make an authentic copy of a database file that is being written to. On receipt of the command to begin the backup, however, Oracle ceases to make direct changes to the database file. It uses a complex combination of rollback segments, buffers, redo logs, and archive logs to store the data until the end backup command is received and the database files are brought back in sync.
Gopu

err not true, the datafile DO get written to, that is so horribly wrong.

All that happens is that the datafile headers get frozen.

Stop writing rubbish

[ams-jamali]

got a thread

http://www.speakeasy.org/~jwilton/or...ot-backup.html

but can't find exact thread from metalink and Reason for Increase in redo log generation during bkup can't find exact thread.

[pando]

When you place a tablespace in backup mode, the Oracle instance notes that a backup is being performed and internally compensates for it. As you know, it is impossible to make an authentic copy of a database file that is being written to. On receipt of the command to begin the backup, however, Oracle ceases to make direct changes to the database file. It uses a complex combination of rollback segments, buffers, redo logs, and archive logs to store the data until the end backup command is received and the database files are brought back in sync.
Gopu

what have you smoked...?!

[FalconRime]

And would someone care to explain the dangers of fogetting to take the tablespace out of backup mode after the data file copy has been performed?...

[davey23uk]

extra redo log generation

believe restarting a database with a tablespace in backup mode will cause problems

[monto1]

but can't find exact thread from metalink and Reason for Increase in redo log generation during bkup can't find exact thread.

It applies all the changes in the block at once to the redologs instead of individual changes when not in backup mode.

[ams-jamali]

Dave., can u explain me briefly on extra redo log generation.

[paragp1981]

read below i hope you get it....

http://www.oraclealchemist.com/oracl...ctured-blocks/