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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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Description:
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.
was:
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
> TVF windowing and EMIT syntax support in Calcite
> ------------------------------------------------
>
> Key: CALCITE-3271
> URL: https://issues.apache.org/jira/browse/CALCITE-3271
> Project: Calcite
> Issue Type: Improvement
> Components: core
> Affects Versions: 1.20.0
> Reporter: Danny Chan
> 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.
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