You're talking about this project, right? https://github.com/deanhiller/playorm I will take a look. However, I don't think using Cassandra's model itself (with CFs / key-values) would be a problem, I just need to know where the advantage relies on. By your answer, my guess is it relies on better performance and more control.
I also saw that if I plan to use Data Stax enterprise to get real time analytics, my data would need to be stored in Cassandra's usual format. It would harder for me use PlayOrm if I am planning to use advanced data stax features, like Solr indexing data on Cassandra without copying columns, realtime, wouldn't it? I don't know much of this Solr feature yet, but my understanding today is it wouldn't be aware of the tables I create with playOrm, just of the column families this framework uses to store the data, right? 2012/9/18 Hiller, Dean <dean.hil...@nrel.gov> > Until Aaron replies, here are my thoughts on the relational piece… > > If everything in my model fits into a relational database, if > my data is structured, would it still be a good idea to use Cassandra? Why? > > The playOrm project explores exactly this issue……A query on 1,000,000 rows > in a single partition only took 60ms AND you can do joins with it's S-SQL > language. The answer is a resounding YES, you can put relational data in > cassandra. The writes are way faster than a DBMS and joins and SQL can be > just as fast and in many cases FASTER on noSQL IF you partition your data > properly. A S-SQL statement looks like so on playOrm > > PARTITIONS t(:partitionId) SELECT t FROM Trades as t where t.numShares > 10 > > You can have as many partitions as you want and a single partition can > have millions of rows though I would not exceed 10 million probably. > > Later, > Dean > > 2012/9/18 aaron morton <aa...@thelastpickle.com<mailto: > aa...@thelastpickle.com>> > Also, I saw a presentation which said that if I don't have rows with more > than a hundred rows in Cassandra, whether I am doing something wrong or I > shouldn't be using Cassandra. > I do not agree with that statement. (I read that as rows with ore than a > hundred _columns_) > > > * I need to support a high volume of writes per second. I might have a > billion writes per hour > > Thats about 280K /sec. Netflix did a benchmark that shows 1.1M/sec > http://techblog.netflix.com/2011/11/benchmarking-cassandra-scalability-on.html > > > * I need to write non-structured data that will be processed later by > hadoop processes to generate structured data from it. Later, I index the > structured data using SOLR or SOLANDRA, so the data can be consulted by my > end user application. Is Cassandra recommended for that, or should I be > thinking in writting directly to HDFS files, for instance? What's the main > advantage I get from storing data in a nosql service like Cassandra, when > compared to storing files into HDFS? > * > > You can query your data using Hadoop easily enough. You may want take a > look at DSE from http://datastax.com/ it makes using Hadoop and Solr > with cassandra easier. > > > * If I don't need to perform complicated queries in Cassandra, should I > store the json-like data just as a column value? I am afraid of doing > something wrong here, as I would need just to store the json file and some > more 5 or 6 fields to query the files later. > * > > Store the data in the way that best supports the read queries you want to > make. If you always read all the fields, or it's a canonical record of > events storing as JSON may be best. If you often get a few fields, and > maybe they are updated, storing each field as a column value may be best. > > > * Does it make sense to you to use hadoop to process data from > Cassandra and store the results in a database, like HBase? Once I have > structured data, is there any reason I should use Cassandra instead of > HBase? > * > > It depends on how many moving parts you are comfortable with. Same for the > questions about HDFS etc. Start with the smallest about of infrastructure. > > Hope that helps. > > ----------------- > Aaron Morton > Freelance Developer > @aaronmorton > http://www.thelastpickle.com > > On 18/09/2012, at 10:28 AM, Marcelo Elias Del Valle <mvall...@gmail.com > <mailto:mvall...@gmail.com>> wrote: > > Hello, > > I am new to Cassandra and I am in doubt if Cassandra is the right > technology to use in the architecture I am defining. Also, I saw a > presentation which said that if I don't have rows with more than a hundred > rows in Cassandra, whether I am doing something wrong or I shouldn't be > using Cassandra. Therefore, it might be the case I am doing something > wrong. If you could help me to find out the answer for these questions by > giving any feedback, it would be highly appreciated. > Here is my need and what I am thinking in using Cassandra for: > > * I need to support a high volume of writes per second. I might have a > billion writes per hour > * I need to write non-structured data that will be processed later by > hadoop processes to generate structured data from it. Later, I index the > structured data using SOLR or SOLANDRA, so the data can be consulted by my > end user application. Is Cassandra recommended for that, or should I be > thinking in writting directly to HDFS files, for instance? What's the main > advantage I get from storing data in a nosql service like Cassandra, when > compared to storing files into HDFS? > * Usually I will write json data associated to an ID and my hadoop > processes will process this data to write data to a database. I have two > doubts here: > * If I don't need to perform complicated queries in Cassandra, > should I store the json-like data just as a column value? I am afraid of > doing something wrong here, as I would need just to store the json file and > some more 5 or 6 fields to query the files later. > * Does it make sense to you to use hadoop to process data from > Cassandra and store the results in a database, like HBase? Once I have > structured data, is there any reason I should use Cassandra instead of > HBase? > > I am sorry if the questions are too dummy, I have been watching a lot > of videos and reading a lot of documentation about Cassandra, but honestly, > more I read more I have questions. > > Thanks in advance. > > Best regards, > -- > Marcelo Elias Del Valle > http://mvalle.com - @mvallebr > > > > > -- > Marcelo Elias Del Valle > http://mvalle.com - @mvallebr > -- Marcelo Elias Del Valle http://mvalle.com - @mvallebr
