Re: 11gR2 rman compression algorithms

From: Jeremy Schneider <jeremy.schneider_at_ardentperf.com>
Date: Thu, 4 Sep 2014 15:03:43 -0400
Message-ID: <CA+fnDAb9=fL6eoWMP4POWQsodYKTxXyMqJFcGN93FcM6yc20Lg_at_mail.gmail.com>

On Thu, Sep 4, 2014 at 2:19 PM, Kevin Jernigan <kevin.jernigan_at_oracle.com>  wrote:

> Why do you need to know the specific algorithms used for backup
> compression?
>

Fair question. It's definitely no substitute for actual testing since compression and performance is so situation-dependent. Nonetheless, compression algorithms are a very well-researched field.

I would argue that knowing if the rman implementations are based on specific well-known algorithms (like deflate, bwt or lzo) will immediately give knowledgeable customers useful insights and help them design better hypothesis and test plans. Also, some people are just geeks and perpetually curious about how things work. <g> But seriously, if RMAN invented some new compression algorithms then fine - but if they have a basis in publicly-known and well-documented algorithms, then why not let smart customers know which is which?

Secondly, it would clarify misinformation on the internet. For example, one of these links must be incorrect because they contradict: http://www.freelists.org/post/oracle-l/11gR2-rman-compression-algorithms,1 http://blog.ronnyegner-consulting.de/2009/11/04/oracle-11g-release-2-rman-compression-comparison/

-Jeremy

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Received on Thu Sep 04 2014 - 21:03:43 CEST