com.hazelcast.org.apache.calcite.rel.stream.Delta Maven / Gradle / Ivy
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* 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 com.hazelcast.org.apache.calcite.rel.stream;
import com.hazelcast.org.apache.calcite.plan.RelOptCluster;
import com.hazelcast.org.apache.calcite.plan.RelTraitSet;
import com.hazelcast.org.apache.calcite.rel.RelInput;
import com.hazelcast.org.apache.calcite.rel.RelNode;
import com.hazelcast.org.apache.calcite.rel.SingleRel;
import com.hazelcast.org.apache.calcite.rel.core.TableScan;
/**
* Relational operator that converts a relation to a stream.
*
* For example, if {@code Orders} is a table, and {@link TableScan}(Orders)
* is a relational operator that returns the current contents of the table,
* then {@link Delta}(TableScan(Orders)) is a relational operator that returns
* all inserts into the table.
*
*
If unrestricted, Delta returns all previous inserts into the table (from
* time -∞ to now) and all future inserts into the table (from now
* to +∞) and never terminates.
*/
public abstract class Delta extends SingleRel {
protected Delta(RelOptCluster cluster, RelTraitSet traits, RelNode input) {
super(cluster, traits, input);
}
/** Creates a Delta by parsing serialized output. */
protected Delta(RelInput input) {
this(input.getCluster(), input.getTraitSet(), input.getInput());
}
}