Evaluating Advanced Compression in RMAN

Hey all,

I'm evaluating the Advanced Compression EE option, specifically for RMAN, in 11.2.0.3 to see if there's any ROI for us. I created a reasonable copy of our Production DB onto a test server and started the trials comparing the three AC compression algorithms to BASIC: LOW, MEDIUM, and HIGH. The HIGH algorithm improved compression by ~500%, but the backup time increased by an ~2000% (I killed the backup before it completed). MEDIUM was decent with a 60% reduction in backup time, and a 30% reduction in backup size. LOW resulted in an 85% improvement in backup time, with 4% better backup size.

The LOW surprised me, as every trial I found on the net showed an _increase_ in backup size when compared to BASIC. I understand everyone's data is different and YMMV, but I didn't expect to be the only trial I could find where LOW was an improvement over BASIC in compression. I'm on AIX, if that matters, and our ERP uses NCHARs to store all string data.

Anyone else see similar results?

Thanks!
Rich

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