When I said to use the BATCH statement I mean't using a query that is
a BATCH statement, so something like:
BEGIN BATCH
INSERT ...;
INSERT ...;
...
APPLY BATCH;
If you want to that from java, you will want to look at the jdbc
driver (http://code.google.com/a/apache-extras.org/p/cassandra-jdbc/),
though I don't know what is the status of the support for CQL3.
On Wed, Jul 11, 2012 at 2:18 PM, Leonid Ilyevsky
<lilyev...@mooncapital.com> wrote:
> Is it OK to put 10000 of update statements in one
> batch, with 50000 question marks in it? The set that many variables?
Yes batch statement can be prepared and in theory there isn't much
limit on the number of update statement (nor question marks) you can
put in one batch. However, the way C* work best is if you do
reasonably sized batches. It's even more true for CQL in the sense
that by using a huge batch statement you'll pay the parsing. So you
probably want to prepare one batch statement with a reasonable number
of statement in it (you'll have to test to find number that give the
best performances, but I would typically start with say 50-100 and see
if the performance are good enough) and reuse that to insert the data.
The other reason why breaking the insert into smallish batches is a
good idea is that it allows you to parallelize the insert using
multiple threads. And you need to parallelize if you want to get the
best out of C*.
--
Sylvain
>
> Maybe I can try small example first, just to see if it works at all.
>
>
>
>
>
> From: Derek Williams [mailto:de...@fyrie.net]
> Sent: Tuesday, July 10, 2012 7:19 PM
> To: user@cassandra.apache.org
> Subject: Re: help using org.apache.cassandra.cql3
>
>
>
> On Tue, Jul 10, 2012 at 3:04 PM, Leonid Ilyevsky <lilyev...@mooncapital.com>
> wrote:
>
> I am trying to use the org.apache.cassandra.cql3 package. Having problem
> connecting to the server using ClientState.
>
> I was not sure what to put in the credentials map (I did not set any
> users/passwords on my server), so I tried setting empty strings for
> “username” and “password”, setting them to bogus values, passing null to the
> login method – there was no difference.
>
> It does not complain at the login(), but then it complains about
> setKeyspace(<my keyspace>), saying that the specified keyspace does not
> exist (it obviously does exist).
>
> The configuration was loaded from cassandra.yaml used by the server.
>
>
>
> I did not have any problem like this when I used
> org.apache.cassandra.thrift.Cassandra.Client .
>
>
>
> What am I doing wrong?
>
>
>
> I think that package just contains server classes. Everything you need
> should be in org.apache.cassandra.thrift.
>
>
>
> To use cql3 I just use the client methods 'execute_cql_query',
> 'prepare_cql_query' and 'execute_prepared_cql_query', after setting cql
> version to '3.0.0'.
>
>
>
>
>
> --
>
> Derek Williams
>
>
>
>
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