[FLINK-6584] [docs] Add ROWTIME and PROCTIME group window functions to documentation.
Project: http://git-wip-us.apache.org/repos/asf/flink/repo Commit: http://git-wip-us.apache.org/repos/asf/flink/commit/14e0948a Tree: http://git-wip-us.apache.org/repos/asf/flink/tree/14e0948a Diff: http://git-wip-us.apache.org/repos/asf/flink/diff/14e0948a Branch: refs/heads/master Commit: 14e0948a94765bcf2cc30c7c3f202a3bcc1f5dca Parents: 2ad8f7e Author: Fabian Hueske <[email protected]> Authored: Tue Oct 24 21:45:06 2017 +0200 Committer: Fabian Hueske <[email protected]> Committed: Wed Oct 25 18:53:30 2017 +0200 ---------------------------------------------------------------------- docs/dev/table/sql.md | 26 ++++++++++++++++++++++---- 1 file changed, 22 insertions(+), 4 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/flink/blob/14e0948a/docs/dev/table/sql.md ---------------------------------------------------------------------- diff --git a/docs/dev/table/sql.md b/docs/dev/table/sql.md index 0eef48b..22eca0d 100644 --- a/docs/dev/table/sql.md +++ b/docs/dev/table/sql.md @@ -660,7 +660,7 @@ For SQL on batch tables, the `time_attr` argument of the group window function m #### Selecting Group Window Start and End Timestamps -The start and end timestamps of group windows can be selected with the following auxiliary functions: +The start and end timestamps of group windows as well as time attributes can be selected with the following auxiliary functions: <table class="table table-bordered"> <thead> @@ -677,7 +677,7 @@ The start and end timestamps of group windows can be selected with the following <code>HOP_START(time_attr, interval, interval)</code><br/> <code>SESSION_START(time_attr, interval)</code><br/> </td> - <td>Returns the start timestamp of the corresponding tumbling, hopping, and session window.</td> + <td><p>Returns the timestamp of the inclusive lower bound of the corresponding tumbling, hopping, or session window.</p></td> </tr> <tr> <td> @@ -685,7 +685,25 @@ The start and end timestamps of group windows can be selected with the following <code>HOP_END(time_attr, interval, interval)</code><br/> <code>SESSION_END(time_attr, interval)</code><br/> </td> - <td>Returns the end timestamp of the corresponding tumbling, hopping, and session window.</td> + <td><p>Returns the timestamp of the <i>exclusive</i> upper bound of the corresponding tumbling, hopping, or session window.</p> + <p><b>Note:</b> The exclusive upper bound timestamp <i>cannot</i> be used as a <a href="streaming.html#time-attributes">rowtime attribute</a> in subsequent time-based operations, such as <a href="#joins">time-windowed joins</a> and <a href="#aggregations">group window or over window aggregations</a>.</p></td> + </tr> + <tr> + <td> + <code>TUMBLE_ROWTIME(time_attr, interval)</code><br/> + <code>HOP_ROWTIME(time_attr, interval, interval)</code><br/> + <code>SESSION_ROWTIME(time_attr, interval)</code><br/> + </td> + <td><p>Returns the timestamp of the <i>inclusive</i> upper bound of the corresponding tumbling, hopping, or session window.</p> + <p>The resulting attribute is a <a href="streaming.html#time-attributes">rowtime attribute</a> that can be used in subsequent time-based operations such as <a href="#joins">time-windowed joins</a> and <a href="#aggregations">group window or over window aggregations</a>.</p></td> + </tr> + <tr> + <td> + <code>TUMBLE_PROCTIME(time_attr, interval)</code><br/> + <code>HOP_PROCTIME(time_attr, interval, interval)</code><br/> + <code>SESSION_PROCTIME(time_attr, interval)</code><br/> + </td> + <td><p>Returns a <a href="streaming.html#time-attributes">proctime attribute</a> that can be used in subsequent time-based operations such as <a href="#joins">time-windowed joins</a> and <a href="#aggregations">group window or over window aggregations</a>.</p></td> </tr> </tbody> </table> @@ -724,7 +742,7 @@ Table result3 = tableEnv.sqlQuery( Table result4 = tableEnv.sqlQuery( "SELECT user, " + " SESSION_START(rowtime, INTERVAL '12' HOUR) AS sStart, " + - " SESSION_END(rowtime, INTERVAL '12' HOUR) AS snd, " + + " SESSION_ROWTIME(rowtime, INTERVAL '12' HOUR) AS snd, " + " SUM(amount) " + "FROM Orders " + "GROUP BY SESSION(rowtime, INTERVAL '12' HOUR), user");
