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Re: SQL backend database scheme

From: Philipp Marek <philipp.marek_at_emerion.com>
Date: Thu, 1 Apr 2010 08:49:34 +0200

Hello Jan!

On Mittwoch, 31. März 2010, Jan Horák wrote:
> 30.3.2010 13:55, Philipp Marek wrote:
> > I looked at that, and I'd like to post two wishes:
> > * Please provide representations with a SHA1 (or similar) field;
> > then it's possible to split blocks on manber-borders, to save
> > space.
>
> Thank you for respond, this is definitely a good point, I will involve it.
Fine, thank you.
Even if no Manber-blocks would be used at first, it would provide consistency
checks.
 
> > * Furthermore, how about allowing the plain data to reside in files?
> > Would make the database much smaller, and then these data blocks
> > could possibly be shared among multiple repositories.
> > (Really easy, too, if they're named by their SHA1, for example).
> > That should allow for zero-copy IO, too (at least for sending data).
>
> The question is, how much faster it would be.. I would like to make a
> simple test to simulate this soon and estimate the percentage difference..
That would be very interesting to me.
I just know of some similar system where bitmaps were fetched out of a
database - instead of just using Apache and static paths the whole data was
transferred multiple times over multiple sockets ...
 
> Another point is a simple backup of the SQL database, using an existed
> global backup system in a company, which is one of the main benefits of
> the SQL backend. Would the external plain data be a problem for global
> backup or not?
That's a good point against that idea, yes.

Regards,

Phil
Received on 2010-04-01 08:50:13 CEST

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