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https://issues.apache.org/jira/browse/CASSANDRA-2878?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13189138#comment-13189138
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Jonathan Ellis commented on CASSANDRA-2878:
-------------------------------------------
So I'm attempting option (1) above, with a method like this:
{code}
. CqlResult execute_partitioned_cql_query(1:required binary query,
2:required string start_token,
3:required string end_token,
4:Compression compression)
{code}
The problem I'm running into is that paginating this CQL-side is enormously
painful. Suppose the last resultset entry is for a composite column (first =
a, second = b) in a row k. Then I need to request my next page as "... WHERE
(key > k OR (key = key AND first >= a AND second > b))." QueryProcessor just
isn't up to this task, even without the complexity of throwing in other
IndexExpressions.
Starting to think that we're better off with (4) for 1.1, after all.
> Allow CQL-based map/reduce
> --------------------------
>
> Key: CASSANDRA-2878
> URL: https://issues.apache.org/jira/browse/CASSANDRA-2878
> Project: Cassandra
> Issue Type: New Feature
> Components: Hadoop
> Reporter: Mck SembWever
> Assignee: Jonathan Ellis
> Priority: Critical
> Fix For: 1.1
>
>
> Currently, when running a MapReduce job against data in a Cassandra data
> store, it reads through all the data for a particular ColumnFamily. This
> could be optimized to only read through those rows that have to do with the
> query.
> Adding CQL support to m/r will allow using an index more simply than trying
> to cram support for more parameters into the job configuration.
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