Archived redo logs shorter than originals

In Oracle 8.1.7.4 (on Solaris 8), archived redo log files were the same size as the original redo log file (i.e., archiving a 10 MB redo log file resulted in a 10 MB archived redo log file in the archive destination directories). In Oracle 10g release 2 (10.2.0.1.0 on Solaris 9), the archived redo log files are all significantly smaller than the originals. With 10 MB redo logs, the largest archived redo log file is about 8.8 MB and most of them are more like 7.5 MB (out of 150 total archived redo logs).

We're archiving to 3 separate destinations and the archived redo logs are identical to each other in all 3 places (but different from the originals). I compared a few originals with their archived copies and other than a few bytes that differ in the first 1 KB, the files are identical until the archived copy ends (1-2 MB before the original file ends). This indicates to me that the reason for the size difference is NOT due to compression of the originals.

Is there some change to the way redo log archiving works between 8i and 10g? Could there be some reason why log file switches would be happening well before the end of the redo log file?

I have a TAR open with Oracle about this, but haven't gotten any useful information so far.

Dave

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David Hollenberg    dhollen@NOmosisSPAM.org    http://www.mosis.org/
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