Cassandra will throw an exception indicating the type is different than the default type.

If you want untyped data, store blobs. Or store in a different column (they're free when empty, after all). Type safety is considered a good thing by many.


On 20 February 2014 17:26, Peter Lin <woolfel@gmail.com> wrote:

I disagree with the sentiment that "thrift is not worth the trouble".

CQL and all SQL inspired dialects limit one's ability to use arbitrary typed data in dynamic columns. With thrift it's easy and straight forward. With CQL there is no way to tell Cassandra the type of the name and value for a dynamic column. You can only set the default type. That means using a "pure cql" approach you can deviate from the default type. Cassandra will throw an exception indicating the type is different than the default type.

Until such time that CQL abandons the shackles of SQL and adds the ability to indicate the column and value type. Something like this

insert into myColumnFamily(staticColumn1, staticColumn2, 20 as int, dynamicColumn as string) into ('text1','text2',30.55 as double, 3500 as long)

This is one area where Thrift is superior to CQL. Having said that, it's valid to use Cassandra "as if" it was a relational database, but then you'd miss out on some of the unique features.




On Thu, Feb 20, 2014 at 12:12 PM, Sylvain Lebresne <sylvain@datastax.com> wrote:
On Thu, Feb 20, 2014 at 2:16 PM, Edward Capriolo <edlinuxguru@gmail.com> wrote:
For what it is worth you schema is simple and uses compact storage. Thus you really dont need anything in cassandra 2.0 as far as i can tell. You might be happier with a stable release like 1.2.something and just hector or astyanax. You are really dealing with many issues you should not have to just to protoype a simple cassandra app.


Of course, if everyone was using that reasoning, no-one would ever test new features and report problems/suggest improvement. So thanks to anyone like Rüdiger that actually tries stuff and take the time to report problems when they think they encounter one. Keep at it, *you* are the one helping Cassandra to get better everyday. 

And you are also right Rüdiger that it's probably not worth the trouble to start with thrift if you're gonna use CQL later. And you definitively should use CQL, it is Cassandra's future.

--
Sylvain 




On Thursday, February 20, 2014, Sylvain Lebresne <sylvain@datastax.com> wrote:
>
>
>
> On Wed, Feb 19, 2014 at 9:38 PM, Rüdiger Klaehn <rklaehn@gmail.com> wrote:
>>
>> I have cloned the cassandra repo, applied the patch, and built it. But when I want to run the bechmark I get an exception. See below. I tried with a non-managed dependency to cassandra-driver-core-2.0.0-rc3-SNAPSHOT-jar-with-dependencies.jar, which I compiled from source because I read that that might help. But that did not make a difference.
>>
>> So currently I don't know how to give the patch a try. Any ideas?
>>
>> cheers,
>>
>> Rüdiger
>>
>> Exception in thread "main" java.lang.IllegalArgumentException: replicate_on_write is not a column defined in this metadata
>>     at com.datastax.driver.core.ColumnDefinitions.getAllIdx(ColumnDefinitions.java:273)
>>     at com.datastax.driver.core.ColumnDefinitions.getFirstIdx(ColumnDefinitions.java:279)
>>     at com.datastax.driver.core.Row.getBool(Row.java:117)
>>     at com.datastax.driver.core.TableMetadata$Options.<init>(TableMetadata.java:474)
>>     at com.datastax.driver.core.TableMetadata.build(TableMetadata.java:107)
>>     at com.datastax.driver.core.Metadata.buildTableMetadata(Metadata.java:128)
>>     at com.datastax.driver.core.Metadata.rebuildSchema(Metadata.java:89)
>>     at com.datastax.driver.core.ControlConnection.refreshSchema(ControlConnection.java:259)
>>     at com.datastax.driver.core.ControlConnection.tryConnect(ControlConnection.java:214)
>>     at com.datastax.driver.core.ControlConnection.reconnectInternal(ControlConnection.java:161)
>>     at com.datastax.driver.core.ControlConnection.connect(ControlConnection.java:77)
>>     at com.datastax.driver.core.Cluster$Manager.init(Cluster.java:890)
>>     at com.datastax.driver.core.Cluster$Manager.newSession(Cluster.java:910)
>>     at com.datastax.driver.core.Cluster$Manager.access$200(Cluster.java:806)
>>     at com.datastax.driver.core.Cluster.connect(Cluster.java:158)
>>     at cassandra.CassandraTestMinimized$delayedInit$body.apply(CassandraTestMinimized.scala:31)
>>     at scala.Function0$class.apply$mcV$sp(Function0.scala:40)
>>     at scala.runtime.AbstractFunction0.apply$mcV$sp(AbstractFunction0.scala:12)
>>     at scala.App$$anonfun$main$1.apply(App.scala:71)
>>     at scala.App$$anonfun$main$1.apply(App.scala:71)
>>     at scala.collection.immutable.List.foreach(List.scala:318)
>>     at scala.collection.generic.TraversableForwarder$class.foreach(TraversableForwarder.scala:32)
>>     at scala.App$class.main(App.scala:71)
>>     at cassandra.CassandraTestMinimized$.main(CassandraTestMinimized.scala:5)
>>     at cassandra.CassandraTestMinimized.main(CassandraTestMinimized.scala)
>
> I believe you've tried the cassandra trunk branch? trunk is basically the future Cassandra 2.1 and the driver is currently unhappy because the replicate_on_write option has been removed in that version. I'm supposed to have fixed that on the driver 2.0 branch like 2 days ago so maybe you're also using a slightly old version of the driver sources in there? Or maybe I've screwed up my fix, I'll double check. But anyway, it would be overall simpler to test with the cassandra-2.0 branch of Cassandra, with which you shouldn't run into that.
> --
> Sylvain

--
Sorry this was sent from mobile. Will do less grammar and spell check than usual.