11gR2 rman compression algorithms

From: Jeremy Schneider <jeremy.schneider_at_ardentperf.com>
Date: Thu, 4 Sep 2014 12:45:22 -0400
Message-ID: <CA+fnDAbo8BeHVrKbrQ-Ruc7ZEme1ivY8RbQTK8uLnFJh7ZZPNQ_at_mail.gmail.com>

In 11gR2, Oracle added some new rman compression algorithms (extra licensing required). They also changed the semantics - calling them low, medium and high.

I'm having a bad search day... I've been searching the docs and the MOS knowledge-base but I haven't found any hints whatsoever about the underlying algorithms. The internet seems full of blog posts claiming that low is LZO, medium is the old ZLIB, and high is a modified BZ2. But I haven't yet found a blog post that has any kind of real citation or even a test case to confirm this. (How hard would it be to pstack an in-progress backup or recovery and check function names?)

I really hate it when the internet is full of stupid blog posts that make claims but don't substantiate them. Especially if the proof isn't anywhere in public.

Does anyone know of an actual doc/mos reference or public test case that substantiates the underlying algorithms?

Probably I'm just missing some obvious link.

-Jeremy

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http://www.freelists.org/webpage/oracle-l Received on Thu Sep 04 2014 - 18:45:22 CEST