On Thu, Feb 20, 2014 at 4:37 PM, Edward Capriolo <edlinuxg...@gmail.com>wrote:
> Recomendations in cassandra have a shelf life of about 1 to 2 years. If > you try to assert a recomendation from year ago you stand a solid chance of > someone telling you there is now a better way. > > Casaandra once loved being a schemaless datastore. Imagine that? > > >> I agree with that. I also think that using CQL hides the basics of how > Cassandra really stores the columns underneath and much of it's > capabilities. People often confuse CQL with SQL and not completely > understand that purpose of CQL is simply make it easy for users to > understand and use Cassandra. Some of the things like INSERT doesn't make > sense from DB standpoint since everything in Cassandra essentially is > MUTATION. > > On Thursday, February 20, 2014, Peter Lin <wool...@gmail.com> wrote: > > > > good example Ed. > > > > I'm so happy to see other people doing things like this. Even if the > official DataStax docs recommend don't mix static and dynamic, to me that's > a huge disservice to Cassandra users. > > > > If someone really wants to stick to relational model, then NewSql is a > better fit, plus gives users the full power of SQL with subqueries, like, > and joins. NewSql can't handle these kinds of use cases due to static > nature of relational tables, row size limit and column limit. > > > > > > > > On Thu, Feb 20, 2014 at 6:18 PM, Edward Capriolo <edlinuxg...@gmail.com> > wrote: > > > > CASSANDRA-6561 is interesting. Though having statically defined columns > are not exactly a solution to do everything in "thrift". > > > > > http://planetcassandra.org/blog/post/poking-around-with-an-idea-ranged-metadata/ > > > > Before collections or CQL existed I did some of these concepts myself. > > > > Say you have a column family named AllMyStuff > > > > columns named "friends_" would be a string and they would be a "Map" of > friends to age > > > > set AllMySuff[edward][friends_bob]=34 > > > > set AllMySuff[edward][friends_sara]=33 > > > > Column name password could be a string > > > > set AllMySuff[edward][password]='mother' > > > > Columns named phone[00] phone[100] would be an array of phone numbers > > > > set AllMySuff[edward][phone[00]]=555-5555' > > > > It was quite easy for me to slice all the phone numbers > > > > startkey: phone > > endkey: phone[100] > > > > But then every column starting with "action_xxxx" could be a page hit > and i could have thousands / ten thousands of these > > > > In many cases CQL has nice/nicer abstractions for some of these things. > But its largest detraction for me is that I can not take this already > existing column family AllMyStuff and 'explain' it to CQL. Its a perfectly > valid way to design something, and might be (probably) is more space > efficient then the system of using composites CQL uses to pack things. I > feel that as a data access language it dictates too much schema, not only > what is in row schema, but it controls the format of the data on disk as > well. Also schema's like mine above are very valid but selecting them into > a table of fixed rows and columns does not map well. > > > > The way hive handles tackles this problem, is that the metadata is > interpreted by a SerDe so that the physical data and the logical definition > are not coupled. > > > > > > > > > > On Thu, Feb 20, 2014 at 5:23 PM, DuyHai Doan <doanduy...@gmail.com> > wrote: > > > > Rüdiger > > > > "SortedMap<byte[], SortedMap<byte[], Pair<Long, byte[]>>" > > > > When using a RandomPartitioner or Murmur3Partitioner, the outer map is > a simple Map, not SortedMap. > > > > The only case you have a SortedMap for row key is when using > OrderPreservingPartitioner, which is clearly not advised for most cases > because of hot spots in the cluster. > > > > > > > > On Thu, Feb 2 > > -- > Sorry this was sent from mobile. Will do less grammar and spell check than > usual. >
