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https://issues.apache.org/jira/browse/KAFKA-5105?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16350970#comment-16350970
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Dmitry Minkovsky edited comment on KAFKA-5105 at 2/2/18 9:52 PM:
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Specifically, from the mailing list archive, Damien writes:
{quote}I think what you are seeing is that the order is not guaranteed across
partitions. When you use Queryable State you are actually querying multiple
underlying stores, i.e., one per partition. The implementation iterates
over one store/partition at a time, so the ordering will appear random.
This could be improved
{quote}
So this is only true when you're using Interactive Queries? Certainly this
cannot be true when you've obtained a state store using
{{ProcessorContext#getStateStore()}}.
*EDIT*:
Yeah I followed the code to {{CompositeReadOnlyKeyValueStore}}. Makes sense.
Still, if my application only writes a certain key range to a certain
partition's store, such that the composite store returned by the interactive
query may include stores for multiple partitions but my data is only on one
partition, then the range should still be ordered?
was (Author: dminkovsky):
Specifically, from the mailing list archive, Damien writes:
{quote}I think what you are seeing is that the order is not guaranteed across
partitions. When you use Queryable State you are actually querying multiple
underlying stores, i.e., one per partition. The implementation iterates
over one store/partition at a time, so the ordering will appear random.
This could be improved
{quote}
So this is only true when you're using Interactive Queries? Certainly this
cannot be true when you've obtained a state store using
{{ProcessorContext#getStateStore()}}.
*EDIT*:
Yeah I followed the code to {{CompositeReadOnlyKeyValueStore}}. Makes sense.
Still, if my application only writes a certain key range to a certain store,
such that the composite store returned by the interactive query may include
stores for multiple partitions but my data is only on one partition, then it
should still be ordered?
> ReadOnlyKeyValueStore range scans are not ordered
> -------------------------------------------------
>
> Key: KAFKA-5105
> URL: https://issues.apache.org/jira/browse/KAFKA-5105
> Project: Kafka
> Issue Type: Improvement
> Components: streams
> Affects Versions: 0.10.2.0
> Reporter: Dmitry Minkovsky
> Priority: Major
>
> Following up with this thread
> https://www.mail-archive.com/users@kafka.apache.org/msg25373.html
> Although ReadOnlyKeyValueStore's #range() is documented not to returns values
> in order, it would be great if it would for keys within a single partition.
> This would facilitate using interactive queries and local state as one would
> use HBase to index data by prefixed keys. If range returned keys in
> lexicographical order, I could use interactive queries for all my data needs
> except search.
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