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Matthias J. Sax commented on KAFKA-12925: ----------------------------------------- [~sagarrao] [~cadonna] [~guozhang] – I had a quick look into this, and it seems `prefixScan` is fundamentally "broken" and unusable? We have a lot of internal "wrapper" classes that implement the base interface and none of them implements the new method to forward the corresponding calls... Seems having a default implementation hid this issue on the original PR... > prefixScan missing from intermediate interfaces > ----------------------------------------------- > > Key: KAFKA-12925 > URL: https://issues.apache.org/jira/browse/KAFKA-12925 > Project: Kafka > Issue Type: Bug > Components: streams > Affects Versions: 2.8.0 > Reporter: Michael Viamari > Priority: Major > > [KIP-614|https://cwiki.apache.org/confluence/display/KAFKA/KIP-614%3A+Add+Prefix+Scan+support+for+State+Stores] > and [KAFKA-10648|https://issues.apache.org/jira/browse/KAFKA-10648] > introduced support for {{prefixScan}} to StateStores. > It seems that many of the intermediate {{StateStore}} interfaces are missing > a definition for {{prefixScan}}, and as such is not accessible in all cases. > For example, when accessing the state stores through a the processor context, > the {{KeyValueStoreReadWriteDecorator}} and associated interfaces do not > define {{prefixScan}} and it falls back to the default implementation in > {{KeyValueStore}}, which throws {{UnsupportedOperationException}}. -- This message was sent by Atlassian Jira (v8.3.4#803005)