TDP Filesize

[Tech]

Hi Everybody,



when I have a look with q b on my saved Oracle Logfiles, they have allways the same filesize.

Example:

API 524.288 K 02.08.2002 11:10:06 MCA7

API 524.288 K 02.08.2002 10:30:03 MCA7

API 524.288 K 30.08.2002 05:00:08 MCA7



The filesize on the Maschine is very different.



Why ?? What is the reason for this ?



Thank you for help.



Best Regards



Tech

 

[DavidWhite]

Hi

I gather you are using RMAN and TDP.

The Oracle logfiles hold old transactions that can be replayed if the DB crashes.

Recovery is to restore DB from backup and rollforward using the logfiles until the DB is consistent (most likely just before crash).

The logfiles are different sizes because there are Oracle parameters to determine when a logfile will switch to the next one. These parameters are time dependent and OS block dependent. So during peak load times these files will switch after the logfile fills up but during quiet times they may switch (half full) after a certain time. Determined by the parameter. See Oracle Concepts doco for more info.

Your backup pieces will be done by RMAN using TDP. There is a RMAN format command "size" that will make sure all backup pieces are that size when written to tape. So it backs up numerous logfiles to the backup piece. In your case size is set to 512MB