Re: Filesystem vs. Raw IO

Mladen Gogala allegedly said,on 28/05/2004 11:00 PM:

> How about solid state disks? There was an article about US government buying
> 1TB solid state disk. I imagine that the speed of writing to that baby is
> not an order of magnitude larger then the speed of writing to memory.

They are exceedingly fast. Best speed you can get on a Oracle benchmark is to put your redo logs in one of these: guaranteed to fly on any writes!

They first write into cache, then firmware controller catches up by writing that to a local disk. Power down? No problem: writes to cache are blocked, while the data in cache is written to that local disk under local battery backup power. Paranoia strikes? No problem: make the local disk mirrored.

Of course there IS a price for all that: don't even dream of putting Tbs in them things....

But it still does not invalidate the premise that writing to memory is STILL faster than writing to disk. And it will be ion the foreseeable future.

-- 
Cheers
Nuno Souto
in sunny Sydney, Australia
dbvision_at_optusnet.com.au
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