M
mfurgal
Guest
Can I help to build trust in online backup? Online backup was introduced back in Progress 6.3 released in 1991. In my experience more people use online backup than people use offline backup. I personally have recovered several databases from online backups without any issues. Technically speaking, online backup works as follows - Backs up the Before Image file - during this part of the process, all update activity is paused - Backed up the data blocks sequentially. - If a block is being requested to be modified, the process that wants to modify it puts the block on the backup queue - Blocks are processed off the backup queue before going to the next block sequentially - When a block that was on the backup queue is reached by the sequential backup, this block is skipped. This means that blocks in the backup archive will likely be out of order. The prorest command handles this gracefully, this is why prorest extends the DB to the high water mark, prior to doing any restore of data blocks. With all this said, the online backup is a snapshot in time at the time the probkup was invoked. Backup alone does not make a solid recovery strategy (offline or online). You need After Imaging (AI) to do this. I hope AI is enabled in your production environment. If it is not, it is like playing with fire. Some day you will get burnt. Mike
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