[
https://issues.apache.org/jira/browse/FLINK-7821?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16216114#comment-16216114
]
ASF GitHub Bot commented on FLINK-7821:
---------------------------------------
Github user xccui commented on a diff in the pull request:
https://github.com/apache/flink/pull/4813#discussion_r146423039
--- Diff: docs/dev/table/tableApi.md ---
@@ -985,19 +985,22 @@ Table result = in.orderBy("a.asc");
<tr>
<td>
- <strong>Limit</strong><br>
+ <strong>Offset & Fetch</strong><br>
<span class="label label-primary">Batch</span>
</td>
<td>
- <p>Similar to a SQL LIMIT clause. Limits a sorted result to a
specified number of records from an offset position. Limit is technically part
of the Order By operator and thus must be preceded by it.</p>
+ <p>Similar to the SQL OFFSET and FETCH clauses. Offset and Fetch
limit the number of records returned from a sorted result. Offset and Fetch are
technically part of the Order By operator and thus must be preceded by it.</p>
{% highlight java %}
Table in = tableEnv.fromDataSet(ds, "a, b, c");
-Table result = in.orderBy("a.asc").limit(3); // returns unlimited number
of records beginning with the 4th record
-{% endhighlight %}
-or
-{% highlight java %}
-Table in = tableEnv.fromDataSet(ds, "a, b, c");
-Table result = in.orderBy("a.asc").limit(3, 5); // returns 5 records
beginning with the 4th record
+
+// returns the first 5 records from the sorted result
+Table result1 = in.orderBy("a.asc").fetch(5);
+
+// returns all records beginning with the 4th record from the sorted result
+Table result2 = in.orderBy("a.asc").offset(3);
+
+// returns the first 5 records beginning with the 10th record from the
sorted result
--- End diff --
Should be 11th?
> Replace Table.limit() by Table.fetch() and Table.offset()
> ---------------------------------------------------------
>
> Key: FLINK-7821
> URL: https://issues.apache.org/jira/browse/FLINK-7821
> Project: Flink
> Issue Type: Improvement
> Components: Table API & SQL
> Affects Versions: 1.4.0
> Reporter: Fabian Hueske
> Assignee: Fabian Hueske
> Priority: Minor
>
> The Table API method limit() exists in two variants:
> - {{limit(offset)}} returns all but the first {{offset}} records.
> - {{limit(offset, fetch)}} returns {{fetch}} records starting from the
> {{offset}}'s record.
> Especially, the behavior of {{limit(offset)}} is confusing because one would
> rather expect a behavior of returning the {{offset}} first records instead of
> all but the {{offset}} first records.
> Moreover, the only way to return the first {{x}} records is to specify a
> {{0}} offset as {{limit(0, x)}}.
> I propose to deprecate and replace both {{limit()}} variants by two new
> methods {{Table.offset(offset)}} and {{Table.fetch(fetch)}} that can be
> combined as follows:
> {code}
> table.orderBy(...).fetch(x)
> table.orderBy(...).offset(x)
> table.orderBy(...).offset(x).fetch(y)
> {code}
--
This message was sent by Atlassian JIRA
(v6.4.14#64029)
