Fwd: Re: HCC in Pillar Storage
Date: Tue, 20 Mar 2012 17:13:12 +0100
The HCC is usually done by the storage; if the storage decides not to do so (e.g. due to CPU load), it will pass the blocks uncompressed and it's then job of the database to uncompress them. So Oracle does not support HCC on non-Exadata/Pillar, but it could do so, but with performance hit.
>> I am wondering because I am not very sure where is HCC done, if it is done
>> in the DB how the hcc algorithm applies for some blocks (pillar) and some
>> not (EVA), if it works shouldnt be a performance hit?