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https://issues.apache.org/jira/browse/CALCITE-3271?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Rui Wang updated CALCITE-3271:
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Affects Version/s: 1.21.0
> Table-valued function windowing and EMIT syntax support in Calcite
> ------------------------------------------------------------------
>
> Key: CALCITE-3271
> URL: https://issues.apache.org/jira/browse/CALCITE-3271
> Project: Calcite
> Issue Type: New Feature
> Components: core
> Affects Versions: 1.20.0, 1.21.0
> Reporter: Danny Chen
> Assignee: Rui Wang
> Priority: Major
>
> Copied from the mailing list:
> Calcite has not implemented the syntax in that paper. I would support an
> effort to add it (unsurprising, since I am a co-author of that paper).
> EMIT STREAM is equivalent to the current SELECT STREAM syntax.
> There is no equivalent in current Calcite of the EMIT AFTER WATERMARK, or
> EMIT STREAM AFTER DELAY.
> HOP, TUMBLE and SESSION are supported in Calcite’s SQL parser, but following
> the paper would be replaced with a table function call. We could need to add
> HOP, TUMBLE and SESSION table functions. We would also need to make the
> system aware of how watermarks flow through these table functions (an area
> that the paper does not go into).
> Julian
> From Rui Wang
> Table-value function windowing means implementing TUMBLE/TOP/SESSION by
> table-value function. As table value functions, TUMBLE/HOP/SESSION assigns
> each row of input table to one or more intervals containing the specified
> watermarked event timestamp column. Those intervals are determined by the
> same way of current windowing support in Calcite: TUMBLE generates fixed
> length, non-overlapping intervals; HOP generates fixed length, overlapping
> intervals; SESSION generates sessionized intervals. The output table of this
> proposed implementation has all columns of input table plus two additional
> columns wstart and wend, which represent the start and the end of the
> interval respectively.
> possible gaps in current Calcite:
> 1. TABLE parameter support in table-value function.
> 2. DESCRIPTOR parameter support in table-value function.
> 3. TUMBLE/TOP/SESSION implemented as built-in table-value function.
> 4. EMIT AFTER WATERMARK and EMIT STREAM AFTER DELAY.
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