phoenix-core/src/main/java/org/apache/phoenix/schema/MetaDataSplitPolicy.java

/*
 * 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,
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 * See the License for the specific language governing permissions and
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 */
package org.apache.phoenix.schema;

import org.apache.hadoop.conf.Configuration;
import org.apache.phoenix.query.QueryServices;
import org.apache.phoenix.query.QueryServicesOptions;

public class MetaDataSplitPolicy extends SplitOnLeadingVarCharColumnsPolicy {

	@Override
	protected boolean shouldSplit() {
		Configuration conf = getConf();
		boolean allowSplittableSystemCatalogRollback = conf.getBoolean
				(QueryServices.ALLOW_SPLITTABLE_SYSTEM_CATALOG_ROLLBACK,
						QueryServicesOptions.DEFAULT_ALLOW_SPLITTABLE_SYSTEM_CATALOG_ROLLBACK);
		boolean allowSystemCatalogToSplit = conf.getBoolean(QueryServices.SYSTEM_CATALOG_SPLITTABLE,
				QueryServicesOptions.DEFAULT_SYSTEM_CATALOG_SPLITTABLE);
		return super.shouldSplit() && allowSystemCatalogToSplit && !allowSplittableSystemCatalogRollback;
	}

	@Override
	protected int getColumnToSplitAt() {
		// SYSTEM.CATALOG rowkey is (tenant id, schema name, table name, column name,
		// column family) ensure all meta data rows for a given schema are in the same
		// region (indexes and tables are in the same schema as we lock the parent table
		// when modifying an index)
		return 2;
	}

}