Thank you for your answers, i need to understand the concept by reading more documents & examples. It will be very helpful if anyone adds various examples (i don't mean the source codes) about the usage areas where HBase fits perfectly.
Thanks again. > Date: Tue, 4 Aug 2009 12:25:16 +0100 > Subject: Re: Some confusions about What HBase is and When to use it? > From: [email protected] > To: [email protected] > > Comments inline > > 2009/8/4 Onur AKTAS <[email protected]>: > > > > I'm confused about the when to use HBase. (Sure I have read everything and > > every link on http://wiki.apache.org/hadoop/Hbase/FAQ) > > Its distributed (when used on Hadoop) and provides efficient database for > > "VERY LARGE" amounts of datas, thats ok. > > > > But as I come from RDBMS world, i want to learn what I can do with HBase > > and how it can affect the quality of my applications. > > > > For example, as I also see on "HBase Schema Design Case Studies" referenced > > by FAQ, "Case 4: user-friends", there is something like > > user: id > > info: name > > info: sex > > info: age > > friend: user_id1 > > friend: user_id2 > > etc.. > > It's possibly worth pointing out, that a userinfo table will quite > likely fit fine inside a relational db like postgres. > > > > > 1- Let me understand the concept, Is there anyway to delete user's id from > > all of his/her friends' friend column? There is no foreign key relation > > then this is the thing that we must handle programmatically? > > > > That's correct, there is no way to do this automatically, there are no > relations in HBase. > > > 2- Is it also useful when the data is small but the calculations on it is > > complex? For example, "calculating the degree of contacts" ? > > > > HBase 0.20 handles small cells fine, eg. I've loaded a 700 million > cell table of integers. You can run map reduce jobs over the whole > table if you want to do processing. > > > 3- Some high traffic applications like making Facebook's, twitter's live > > status feed with HBase is possible? (Distribution of feeds to friend lists > > etc.) > > > > I can't really answer that, as I haven't used it in this way. It has a > really good write throughput though. You could optimise for this case. > In memory tables etcetera. You'd want to not run any map reduce over > it at the same time. > > > Or > > Its main goal is to analyse whole data and calculations for the internal > > use? Not for serving them to users in realtime like RDBMS? > > HBase 0.20 can handle real time now. See > http://devblog.streamy.com/2009/07/24/streamy-hadoop-summit-hbase-goes-realtime/ > > > > > > Thank you so much. > > > hope that helps. > ~Tim _________________________________________________________________ Windows Live tüm arkadaşlarınızla tek bir yerden iletişim kurmanıza yardımcı olur. http://www.microsoft.com/turkiye/windows/windowslive/products/social-network-connector.aspx
