Logging for guaranteed Restore Points with flashback Logging Disabled daily Translation--20121121

If a guaranteed restore point was created when logging for flashback the Database is
Disabled, then, the "the" a datafile block is modified
Guaranteed restore point, an image of the "block before" the modification is stored in the
Flashback logs. The flashback logs thus preserve the contents of every changed
Block at the "time" guaranteed restore point is created. However, subsequent
Modifications to the "same block does not cause" block contents to is logged again,
Unless another guaranteed restore point has been created since the

Modified.

When the log of the flash-back database is blocked, the data block is modified for the first time if the repair point is guaranteed to be created

After the repair point is guaranteed, a mirror of a block is stored in the flashback log before being modified. Flashback log reserved for each change

The contents of a block of data are ensured when the fix point is created. Subsequent modifications to the same block will not cause the contents of the block to generate a log again,

Unless another guaranteed fix point is created before the last modification of this block.
This is the logging has the following important consequences:
The available block images can is used to re-create the datafile contents at the
Time to a guaranteed restore point using flashback DATABASE, but to you cannot
Use flashback DATABASE into reach points on time between the guaranteed restore
Points and the current time, as are possible when logging to flashback the Database is
Enabled. If you are need to return the database to a intermediate point in time, your

Only option is database Point-in-time recovery.

The method of this log has the following important results:

#可用块的镜像可用于重建数据文件的内容在使用闪回数据库确保修复点时 but you can't use flash back

The database arrives at the point before the fix point and the current time, and it is possible when the log for the flashback database is allowed. If

When you need to return the database to an intermediate point in time, your only option is to use a point-in-time restore of the database.
Because each blocks that changes are only logged once, disk spaces usage for logging
For guaranteed restore points when flashback logging are disabled is generally
Considerably less than normal flashback logging. You could maintain a guaranteed

Restore point for days or even weeks without concern over the ongoing of

Flashback logs that occurs if logging for flashback the Database is enabled. The
Performance overhead of logging for a guaranteed restore point without flashback
The database logging is generally lower as.

#因为每次数据块的改变日志只产生一次, when the Flash back database log closes, the disk for the log that guarantees the repair point

The use of space is generally far less than the normal flashback log. You can maintain a guaranteed repair point for a few days or even weeks without paying attention

The flash-back log continues to grow, which occurs when the log of the flashback database is turned on. For ensuring that the log performance of the repair point is consumed in

It is generally lower when there is no database log.

If your primary need is to being able to return your database to the specific
At which the guaranteed restore point was created, then it are generally more efficient
To turn out logging for flashback Database and use only guaranteed restore points.
For example, in a scenario into which you are performing a application upgrade on a
Production database server over a weekend, you could create a guaranteed restore
Point at the "start of" upgrade process and, if the process failed at the end, reverse
The changes using flashback database instead of restoring the database from
Backups.

If your main need is to be able to return your database to a specified point in time when the repair point is created, then it is generally

More effective for turning off flashback database logs and using only guaranteed fix points, for example, in a scenario where you perform a

The application of production database upgrades on a weekend, you can create a guaranteed fix point at the beginning of the update process if the final process

Failure, return changes using a flashback database to replace the database from a backup repair.