/
SupportsLimitPushDown.java
44 lines (40 loc) · 1.72 KB
/
SupportsLimitPushDown.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.flink.table.connector.source.abilities;
import org.apache.flink.annotation.PublicEvolving;
import org.apache.flink.table.connector.source.ScanTableSource;
/**
* Enables to push down a limit (the expected maximum number of produced records) into a {@link
* ScanTableSource}.
*
* <p>It might be beneficial to perform the limiting as early as possible in order to be close to
* the actual data generation.
*
* <p>A source can perform the limiting on a best-effort basis. During runtime, it must not
* guarantee that the number of emitted records is less than or equal to the limit.
*
* <p>Regardless if this interface is implemented or not, a limit is also applied in a subsequent
* operation after the source.
*/
@PublicEvolving
public interface SupportsLimitPushDown {
/**
* Provides the expected maximum number of produced records for limiting on a best-effort basis.
*/
void applyLimit(long limit);
}