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From Edward Capriolo <edlinuxg...@gmail.com>
Subject Re: Performance problem with large wide row inserts using CQL
Date Thu, 20 Feb 2014 19:31:46 GMT
The only thing you really can not do CQL3 loses some of the concept of CQL2
metadata, namedly the default validation and then column specific
validation.

In cassandra-cql we can say (butchering the syntax)

create column family x
DEFAULT_VALIDATOR = UTF8Type
columns named y are int
columns named z are string

You can do this in CQL.:
create table x (
rowkey blob,
column blob,
value blob,
primary key(rowkey,column) using compact storage ;

But you lost the concept of columns named y validate as int. Everything is
just blob as far as CQL understands it. That being said in the schema
presented nothing stops the user from implementing their design in either
"system"



On Thu, Feb 20, 2014 at 12:46 PM, Sylvain Lebresne <sylvain@datastax.com>wrote:

> On Thu, Feb 20, 2014 at 6:26 PM, Peter Lin <woolfel@gmail.com> wrote:
>
>>
>> I disagree with the sentiment that "thrift is not worth the trouble".
>>
>
> Way to quote only part of my sentence and get mental on it. My full
> sentence was "it's probably not worth the trouble to start with thrift if
> you're gonna use CQL later".
>
>
>>
>> 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.
>>
>
> Man, if I had a nickel every time someone came on that mailing list
> pretending that something was possible with thrift and not CQL ... I will
> claim this: with CASSANDRA-6561 and CASSANDRA-4851 that just got in, there
> is *nothing* that thrift can do that CQL cannot. But well, what do I know
> about Cassandra.
>
> --
> Sylvain
>
>
>
>>
>>
>>
>>
>> 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.
>>>>
>>>
>>>
>>
>

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