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https://issues.apache.org/jira/browse/CALCITE-4146?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Danny Chen updated CALCITE-4146:
--------------------------------
Description:
The goal is to support the following syntax:
{code:sql}
SELECT clause
FROM TUMBLE/HOP/SESSION
[EMIT]
{code}
EMIT Syntax is proposed in [One SQL to Rule Them
All|https://arxiv.org/pdf/1905.12133.pdf]. This idea proposes a way to allow
streaming SQL queries control materialization latency.
Regarding the types of emit strategies, due to limit pages, that paper only
lists two strategies, and Calcite should support at least four categories:
# Event time triggers. Emitting depends on the relationship between
watermark and event timestamp of events. Handling late data is also included in
this category.
# Processing time triggers. Emitting depends on the system clock. This is
a natural idea of emitting. E.g. emit the current result every hour without
considering if data in a window is already complete.
# data-driven triggers. E.g. emit when accumulated events exceed a
threshold (e.g. emit when have acculucated 1000 events)
# Composite triggers. There is a need to concat 1, 2, 3 by OR and AND to
achieve better latency control.
There are more context discussed in
[CALCITE-3272|https://issues.apache.org/jira/browse/CALCITE-3272?focusedCommentId=17166580&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-17166580]
and the [EMIT syntax proposal for event-timestamp semantic
windowing|https://lists.apache.org/thread.html/r5bd9a6f7af2c0cd81aecd4de512fd889fbf15f112cc3704f188b1d4f%40%3Cdev.calcite.apache.org%3E]
email thread.
was:
The goal is to support the following syntax:
{code:sql}
SELECT clause
FROM TUMBLE/HOP/SESSION
[EMIT]
{code}
EMIT Syntax is proposed in [One SQL to Rule Them
All|https://arxiv.org/pdf/1905.12133.pdf]. This idea proposes a way to allow
streaming SQL queries control materialization latency.
Regarding the types of emit strategies, due to limit pages, that paper only
lists two strategies, and Calcite should support at least four categories:
1. Event time triggers. Emitting depends on the relationship between
watermark and event timestamp of events. Handling late data is also included
in this category.
2. Processing time triggers. Emitting depends on the system clock. This is
a natural idea of emitting. E.g. emit the current result every hour without
considering if data in a window is already complete.
3. data-driven triggers. E.g. emit when accumulated events exceed a
threshold (e.g. emit when have acculucated 1000 events)
4. Composite triggers. There is a need to concat 1, 2, 3 by OR and AND to
achieve better latency control.
There are more context discussed in
[CALCITE-3272|https://issues.apache.org/jira/browse/CALCITE-3272?focusedCommentId=17166580&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-17166580]
and the [EMIT syntax proposal for event-timestamp semantic
windowing|https://lists.apache.org/thread.html/r5bd9a6f7af2c0cd81aecd4de512fd889fbf15f112cc3704f188b1d4f%40%3Cdev.calcite.apache.org%3E]
email thread.
> Implement EMIT Syntax
> ---------------------
>
> Key: CALCITE-4146
> URL: https://issues.apache.org/jira/browse/CALCITE-4146
> Project: Calcite
> Issue Type: New Feature
> Reporter: Rui Wang
> Assignee: Rui Wang
> Priority: Major
>
> The goal is to support the following syntax:
> {code:sql}
> SELECT clause
> FROM TUMBLE/HOP/SESSION
> [EMIT]
> {code}
> EMIT Syntax is proposed in [One SQL to Rule Them
> All|https://arxiv.org/pdf/1905.12133.pdf]. This idea proposes a way to allow
> streaming SQL queries control materialization latency.
> Regarding the types of emit strategies, due to limit pages, that paper only
> lists two strategies, and Calcite should support at least four categories:
> # Event time triggers. Emitting depends on the relationship between
> watermark and event timestamp of events. Handling late data is also included
> in this category.
> # Processing time triggers. Emitting depends on the system clock. This is
> a natural idea of emitting. E.g. emit the current result every hour without
> considering if data in a window is already complete.
> # data-driven triggers. E.g. emit when accumulated events exceed a
> threshold (e.g. emit when have acculucated 1000 events)
> # Composite triggers. There is a need to concat 1, 2, 3 by OR and AND to
> achieve better latency control.
> There are more context discussed in
> [CALCITE-3272|https://issues.apache.org/jira/browse/CALCITE-3272?focusedCommentId=17166580&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-17166580]
> and the [EMIT syntax proposal for event-timestamp semantic
> windowing|https://lists.apache.org/thread.html/r5bd9a6f7af2c0cd81aecd4de512fd889fbf15f112cc3704f188b1d4f%40%3Cdev.calcite.apache.org%3E]
> email thread.
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