com.couchbase.client.core.api.query.CoreQueryScanConsistency Maven / Gradle / Ivy
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/*
* Copyright (c) 2023 Couchbase, Inc.
*
* Licensed 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.couchbase.client.core.api.query;
import com.couchbase.client.core.annotation.Stability;
/**
* The possible values for scan consistency in a N1QL request.
*/
@Stability.Internal
public enum CoreQueryScanConsistency {
/**
* The indexer will return whatever state it has to the query engine at the time of query.
*
* This is the default (for single-statement requests). No timestamp vector is used in the index scan. This is also
* the fastest mode, because we avoid the cost of obtaining the vector, and we also avoid any wait for the index to
* catch up to the vector.
*/
NOT_BOUNDED {
@Override
public String toString() {
return "not_bounded";
}
},
/**
* The indexer will wait until all mutations have been processed at the time of request before returning to the
* query engine.
*
* This implements strong consistency per request. Before processing the request, a current vector is obtained. The
* vector is used as a lower bound for the statements in the request. If there are DML statements in the request,
* RYOW ("read your own write") is also applied within the request.
*/
REQUEST_PLUS {
@Override
public String toString() {
return "request_plus";
}
}
}