//---------------------------------------------------------------------------
//	Greenplum Database
//	Copyright (C) 2023 VMware, Inc. or its affiliates.
//
//	@filename:
//		CLeftJoinPruningPreprocessor.h
//
//	@doc:
//		Preprocessing routines of left join pruning
//---------------------------------------------------------------------------

#ifndef GPOPT_CLeftJoinPruningPreprocessor_H
#define GPOPT_CLeftJoinPruningPreprocessor_H

#include "gpos/base.h"

#include "gpopt/base/CColRefSet.h"
#include "gpopt/operators/CExpression.h"

namespace gpopt
{
class CLeftJoinPruningPreprocessor
{
private:
	static CExpression *PexprJoinPruningScalarSubquery(
		CMemoryPool *mp, CExpression *pexprScalar);

	static void ComputeOutputColumns(const CExpression *pexpr,
									 const CColRefSet *derived_output_columns,
									 CColRefSet *output_columns,
									 CColRefSet *childs_output_columns,
									 const CColRefSet *pcrsOutput);

	static CExpression *JoinPruningTreeTraversal(
		CMemoryPool *mp, const CExpression *pexpr, CExpressionArray *pdrgpexpr,
		const CColRefSet *childs_output_columns);

	static CExpression *PexprCheckLeftOuterJoinPruningConditions(
		CMemoryPool *mp, CExpression *pexprNew, CColRefSet *output_columns);

	static BOOL CheckJoinPruningCondOnInnerRel(const CExpression *pexprNew,
											   CColRefSet *output_columns);

	static BOOL CheckJoinPruningCondOnJoinCond(CMemoryPool *mp,
											   const CExpression *pexprNew,
											   CColRefSet *result);

	static BOOL CheckAndCondInJoinCond(CMemoryPool *mp,
									   const CExpression *join_cond,
									   const CColRefSet *inner_unique_keys,
									   CColRefSet *result,
									   const CColRefSet *outer_rel_columns);

	static void CheckUniqueKeyInJoinCond(CColRefSet *inner_columns,
										 const CColRefSet *usedColumns,
										 CColRefSet *result,
										 const CColRefSet *inner_unique_keys,
										 const CColRefSet *outer_rel_columns);

	static BOOL CheckForFullUniqueKeySetInInnerRel(CMemoryPool *mp,
												   const CExpression *pexprNew,
												   const CColRefSet *result);

public:
	CLeftJoinPruningPreprocessor(const CLeftJoinPruningPreprocessor &) = delete;

	// Main Driver
	static CExpression *PexprPreprocess(CMemoryPool *mp, CExpression *pexpr,
										const CColRefSet *pcrsOutput);
};	// class CLeftJoinPruningPreprocessor
}  // namespace gpopt


#endif