com.netease.arctic.shade.org.apache.iceberg.RowLevelOperationMode Maven / Gradle / Ivy
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* 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,
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*/
package com.netease.arctic.shade.org.apache.iceberg;
import com.netease.arctic.shade.org.apache.iceberg.relocated.com.google.common.base.Preconditions;
/**
* Iceberg supports two ways to modify records in a table: copy-on-write and merge-on-read.
*
* In copy-on-write, changes are materialized immediately and matching data files are replaced with
* new data files that represent the new table state. For example, if there is a record that
* has to be deleted, the data file that contains this record has to be replaced with another
* data file without that record. All unchanged rows have to be copied over to the new data file.
*
* In merge-on-read, changes aren't materialized immediately. Instead, IDs of deleted and updated
* records are written into delete files that are applied during reads and updated/inserted records
* are written into new data files that are committed together with the delete files.
*
* Copy-on-write changes tend to consume more time and resources during writes but don't introduce any
* performance overhead during reads. Merge-on-read operations, on the other hand, tend to be much
* faster during writes but require more time and resources to apply delete files during reads.
*/
public enum RowLevelOperationMode {
COPY_ON_WRITE, MERGE_ON_READ;
public static RowLevelOperationMode fromName(String modeName) {
Preconditions.checkArgument(modeName != null, "Mode name is null");
if ("copy-on-write".equalsIgnoreCase(modeName)) {
return COPY_ON_WRITE;
} else if ("merge-on-read".equalsIgnoreCase(modeName)) {
return MERGE_ON_READ;
} else {
throw new IllegalArgumentException("Unknown row-level operation mode: " + modeName);
}
}
}