Re: [Sedna-discussion] Sedna 3.0
Sedna is a native full-featured XML database management system.
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From: Steve H. <how...@gm...> - 2008-03-30 16:52:50
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Hello Maxim Grinev, > In Sedna 3.0 you can run read-only transaction which will not conflict > with any write transactions. So it allows you to run export utility which > will not stop other transactions. It is sort of Hot Backup. We are also > thinking about implementing it at physical level (i.e. copying data blocks > instead of exporting to XML) to speed up recovery process. Physical-level > recovery can be implemented using the same mechanism so I hope we will do > it soon. Currently I was afraid of deplying anything on real field since I'd have to stop the database (and application) in order to backup the data. > - Binary blobs > Binary Blobs is not implemented yet. I think it will be one of our next > features. That's going to be great! Binary storage is the Achilles' heel of XML databases. > - Automatic index usage > No. We don't want to implement this. It requires complex optimization which > is error-prone. Also we believe that this feature is not critical. I understand, however it would be a nice feature, specially for newcomers. > - More modest/automated memory usage > What do you mean under this? Well, Sedna uses a lot of ram memory - 100Mb for each database. Is that really necessary ? I think it would manage it's memory as needed, dinamically, and being able to shrink/grow it's own bufffers/cache as needed. If you take PostgreSQL, for instance, it has global memory configurations, no matter how many databases are being handled. With the current Sedna implementation, if I have 5 databases, I'd be using 500Mb of ram, which is a lot if you use a remote VPS/dedicated server. I believe 100Mb could be much larger then data managed by Sedna on many real world databases... so why fixing on that length ? -- Best Regards, Steve Howe |