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https://issues.apache.org/jira/browse/CASSANDRA-8483?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14246723#comment-14246723
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Benedict commented on CASSANDRA-8483:
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Yes, I agree we'll need a lot of changes elsewhere, but the goal here is only
to introduce the capability to the clients so they're ready well ahead of time,
and so we can hopefully taper off new protocol versions.
We do currently offer isolation for CL>ONE if you read from a single partition,
since we corroborate all sources have the same digest and only actually return
the results from a single replica that is read with isolation. Doing so for a
streaming read would certainly be more difficult, but I don't think any (or
much) more so than the streaming reads themselves, which will need to deal with
streaming digests and read repair anyway.
> Support streaming results
> -------------------------
>
> Key: CASSANDRA-8483
> URL: https://issues.apache.org/jira/browse/CASSANDRA-8483
> Project: Cassandra
> Issue Type: Sub-task
> Components: Core
> Reporter: Benedict
> Fix For: 3.0
>
>
> Currently we stream the number of rows back to the client before serializing,
> which means we need to know how many there are before doing so, which means
> materializing the entire resultset. We currently get around this with paging
> which attempts to restrict the amount of materialization done in any step,
> but supporting streaming entire result sets in one native transport "action"
> without materializing them all upfront would remove the need for paging in
> many cases, and would permit resultsets to be streamed _with isolation_,
> which most users probably don't realise is broken by paging.
> We can't use this change yet, but the sooner support for this is introduced
> to the protocol, the more likely it is clients will be able to make use of
> streaming reads once we're actually able to deliver them.
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