org.apache.hadoop.hive.ql.optimizer.Transform Maven / Gradle / Ivy
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* http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.hadoop.hive.ql.optimizer;
import org.apache.hadoop.hive.ql.log.PerfLogger;
import org.apache.hadoop.hive.ql.parse.ParseContext;
import org.apache.hadoop.hive.ql.parse.SemanticException;
import org.apache.hadoop.hive.ql.session.SessionState;
/**
* Optimizer interface. All the rule-based optimizations implement this
* interface. All the transformations are invoked sequentially. They take the
* current parse context (which contains the operator tree among other things),
* perform all the optimizations, and then return the updated parse context.
*/
public abstract class Transform {
/**
* All transformation steps implement this interface.
*
* @param pctx
* input parse context
* @return ParseContext
* @throws SemanticException
*/
public abstract ParseContext transform(ParseContext pctx) throws SemanticException;
public void beginPerfLogging() {
PerfLogger perfLogger = SessionState.getPerfLogger();
perfLogger.perfLogBegin(this.getClass().getName(), PerfLogger.OPTIMIZER);
}
public void endPerfLogging() {
PerfLogger perfLogger = SessionState.getPerfLogger();
perfLogger.perfLogEnd(this.getClass().getName(), PerfLogger.OPTIMIZER);
}
public void endPerfLogging(String additionalInfo) {
PerfLogger perfLogger = SessionState.getPerfLogger();
perfLogger.perfLogEnd(this.getClass().getName(), PerfLogger.OPTIMIZER, additionalInfo);
}
}