Re: Block-level CRC checks

On Mon, Dec 15, 2008 at 12:30 PM, Alvaro Herrera
<alvherre@commandprompt.com> wrote:
>> How hard would it be to just take an exclusive lock on the page when setting
>> all these hint bits?
>
> I guess it will be intolerably slow then.  If we were to say "we have
> CRC now, but if you enable it you have 1% of the performance" we will
> get laughed at.

Well, Oracle does tell users that enabling full CRC checking will cost
~5% performance overhead, which is reasonable to me.  I'm not
pessimistic enough to think we'd be down to 1% the performance of a
non-CRC enabled system, but the locking overhead would probably be
fairly high.  The problem is, at this point, we don't really know what
the impact would be either way :(

-- 
Jonah H. Harris, Senior DBA
myYearbook.com