[jira] [Commented] (CALCITE-1645) Row per match syntax support for MATCH_RECOGNIZE

["Zhiqiang He (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/CALCITE-1645?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16016987#comment-16016987 ] 

Zhiqiang He commented on CALCITE-1645:
--------------------------------------

https://github.com/apache/calcite/pull/452
please review it. thanks. 

> Row per match  syntax support for MATCH_RECOGNIZE
> -------------------------------------------------
>
>                 Key: CALCITE-1645
>                 URL: https://issues.apache.org/jira/browse/CALCITE-1645
>             Project: Calcite
>          Issue Type: Sub-task
>          Components: core
>    Affects Versions: 1.11.0
>            Reporter: Zhiqiang He
>            Assignee: Zhiqiang He
>              Labels: features
>
> h1. [ONE ROW | ALL ROWS] PER MATCH: Choosing Summaries or Details for Each Match
> You will sometimes want summary data about the matches and other times need details. You can do that with the following SQL:
> * ONE ROW PER MATCH
> Each match produces one summary row. This is the default.
> * ALL ROWS PER MATCH
> A match spanning multiple rows will produce one output row for each row in the match.
> The output is explained in "Row Pattern Output".
> The MATCH_RECOGNIZE clause may find a match with zero rows. For an empty match, ONE ROW PER MATCH returns a summary row: the PARTITION BY columns take the values from the row where the empty match occurs, and the measure columns are evaluated over an empty set of rows.
> ALL ROWS PER MATCH has three suboptions:
> * ALL ROWS PER MATCH SHOW EMPTY MATCHES
> * ALL ROWS PER MATCH OMIT EMPTY MATCHES
> * ALL ROWS PER MATCH WITH UNMATCHED ROWS



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