Thanks themanatuf, This is awesome link... really they explained data model very nicely especially for folks from RDMS background.
Regards, Sonia On Sat, Jul 24, 2010 at 4:17 AM, Uncle Mantis <uncleman...@gmail.com> wrote: > I want to point out my up hill battle tips. > > Make some friends in the Freenode #Cassandra IRC channel. > > Stop hunting for formal documentation and just read all articles and > examples you can get a hold if regardless of it is Java or PHP or Ruby. > > Take a look at Thrift and it's many wrappers. > > There are some all star players in the community that you will continue to > run into. Listen to them. Do not be thick headed. Follow their advice. They > know what they are talking about. The last thing they want you to do is take > the hard road if you do not have to. > > Shouts to Benjamin Black and the rest of the #Cassandra crew that has > helped me and put up with me. > > Sent from my iPhone > > On Jul 24, 2010, at 12:50 AM, "themana...@juno.com" <themana...@juno.com> > wrote: > > > Sonia, > > > > If you haven't visited the site below, I think it does the best job of > explaining what Cassandra is all about: > > > > http://arin.me/blog/wtf-is-a-supercolumn-cassandra-data-model > > > > Consider a group of ColumFamilies within a Keyspace like a group of > tables in a database. > > > > CompareWith tells Cassandra how to sort the data and it is sorted by the > types you described. So if you tell it to sort by UTF8Type it will consider > the in the column that matches your row key to be UTF8 data and will sort > accordingly. > > > > > > > > From: sonia gehlot <sonia.geh...@gmail.com> > > To: user@cassandra.apache.org > > Subject: Cassandra basics > > Date: Fri, 23 Jul 2010 15:48:12 -0700 > > > > Hi Guys, > > > > Recently I have started reading about Cassandra from the material > available on net. But I have very confused with the basic understanding of > Cassandra. > > I understand columnFamilies, supper columnFamilies but I have no clear > understanding of > > > > > > <Keyspace Name="Twitter"> > > <ColumnFamily CompareWith="UTF8Type" Name="Statuses" /> > > <ColumnFamily CompareWith="UTF8Type" Name="StatusAudits" /> > > > > > > <ColumnFamily CompareWith="UTF8Type" Name="StatusRelationships" > CompareSubcolumnsWith="TimeUUIDType" ColumnType="Super" /> > > <ColumnFamily CompareWith="UTF8Type" Name="Users" /> > > > > > > <ColumnFamily CompareWith="UTF8Type" Name="UserRelationships" > CompareSubcolumnsWith="TimeUUIDType" ColumnType="Super" /> > > </Keyspace> > > > > > > <ColumnFamily Name = "LocationUserIndexSCF" > > CompareWith = "UTF8Types" > > CompareSubcolumnsWith= "UTF8Type" > > ColumnType = "Super"/> > > > > 1. I don't understand what is this "CompareWith", > "CompareSuperColumnWith", "CompareSubcolumnsWith" etc is? > > > > 2. What is "UTF8Type", "TimeUUIDType", "LongType", "ASCIIType" etc.. is > these are datatypes? as we have datatype in SQL, if so then is this is > datatype of value stored in this column family? > > > > > > > > May be I am getting confused because I am mixing my Relational databases > fundamentals with distributed. > > Please If someone can explain me significance of these things then it > would be very helpful. > > > > Thanks in advance. > > > > Please reply. > > > > Sonia > > > > > > ____________________________________________________________ > > FIRE SALE: iPads for $23.74? > > SPECIAL REPORT: iPads are being auctioned for an incredible 85% off! > > http://thirdpartyoffers.juno.com/TGL3131/4c4a393b224513eab65st05duc >
