If you haven't already read it, read the Google Bigtable paper. On 8/4/09, Onur AKTAS <[email protected]> wrote: > > 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
-- Amandeep Khurana Computer Science Graduate Student University of California, Santa Cruz
