src/include/nodes/nodes.h - hawq - Git at Google

 /*
  * 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,
  * 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.
  */

 /*-------------------------------------------------------------------------
  *
  * nodes.h
  *	  Definitions for tagged nodes.
  *
  *
  * Portions Copyright (c) 2005-2009, Greenplum inc
  * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * $PostgreSQL: pgsql/src/include/nodes/nodes.h,v 1.188 2006/09/28 20:51:42 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
 #ifndef NODES_H
 #define NODES_H

 /*
  * The first field of every node is NodeTag. Each node created (with makeNode)
  * will have one of the following tags as the value of its first field.
  *
  * Note that the numbers of the node tags are not contiguous. We left holes
  * here so that we can add more tags without changing the existing enum's.
  * (Since node tag numbers never exist outside backend memory, there's no
  * real harm in renumbering, it just costs a full rebuild ...)
  */
 typedef enum NodeTag
 {
 	T_Invalid = 0,

 	/*
 	 * TAGS FOR EXECUTOR NODES (execnodes.h)
 	 */
 	T_IndexInfo = 10,
 	T_ExprContext,
 	T_ProjectionInfo,
 	T_JunkFilter,
 	T_ResultRelInfo,
 	T_EState,
 	T_TupleTableSlot,
 	T_CdbProcess,
 	T_Slice,
 	T_SliceTable,
 	T_ShareNodeEntry,
 	T_PartitionState,

 	/*
 	 * TAGS FOR PLAN NODES (plannodes.h)
 	 */
 	T_Plan = 100,
 	T_Scan,
 	T_Join,
 	T_CteScan,

 	/* Real plan node starts below.  Scan and Join are "Virtal nodes",
 	 * It will take the form of IndexScan, SeqScan, etc.
 	 * CteScan will take the form of SubqueryScan.
 	 */
 	T_Result,
 	T_Plan_Start = T_Result,
 	T_Append,
 	T_Sequence,
 	T_BitmapAnd,
 	T_BitmapOr,
 	T_SeqScan,
 	T_ExternalScan,
 	T_AppendOnlyScan,
 	T_TableScan,
 	T_DynamicTableScan,
 	T_ParquetScan,
 	T_IndexScan,
 	T_DynamicIndexScan,
 	T_BitmapIndexScan,
 	T_BitmapHeapScan,
 	T_BitmapTableScan,
 	T_TidScan,
 	T_SubqueryScan,
 	T_FunctionScan,
 	T_TableFunctionScan,
 	T_ValuesScan,
 	T_NestLoop,
 	T_MergeJoin,
 	T_HashJoin,
 	T_Material,
 	T_Sort,
 	T_Agg,
 	T_Unique,
 	T_Hash,
 	T_SetOp,
 	T_Limit,
 	T_Motion,
 	T_ShareInputScan,
 	T_Window,
 	T_Repeat,
 	T_DML,
 	T_SplitUpdate,
 	T_RowTrigger,
 	T_AssertOp,
 	T_PartitionSelector,
 	T_MagmaIndexScan,
 	T_MagmaIndexOnlyScan,
 	T_MagmaBitmapScan,
 	T_OrcIndexScan,
 	T_OrcIndexOnlyScan,
 	T_Plan_End,
 	/* this one isn't a subclass of Plan: */
 	T_PlanInvalItem,

 	/*
 	 * TAGS FOR PLAN STATE NODES (execnodes.h)
 	 *
 	 * These should correspond one-to-one with Plan node types.
 	 */
 	T_PlanState = 200,
 	T_ScanState,
 	T_JoinState,

 	/* Real plan node starts below.  Scan and Join are "Virtal nodes",
 	 * It will take the form of IndexScan, SeqScan, etc.
 	 */
 	T_ResultState,
 	T_PlanState_Start = T_ResultState,
 	T_AppendState,
 	T_SequenceState,
 	T_BitmapAndState,
 	T_BitmapOrState,
 	T_SeqScanState,
 	T_AppendOnlyScanState,
 	T_ParquetScanState,
 	T_TableScanState,
 	T_DynamicTableScanState,
 	T_ExternalScanState,
 	T_IndexScanState,
 	T_DynamicIndexScanState,
 	T_BitmapIndexScanState,
 	T_BitmapHeapScanState,
 	T_BitmapTableScanState,
 	T_TidScanState,
 	T_SubqueryScanState,
 	T_FunctionScanState,
 	T_TableFunctionState,
 	T_ValuesScanState,
 	T_NestLoopState,
 	T_MergeJoinState,
 	T_HashJoinState,
 	T_MaterialState,
 	T_SortState,
 	T_AggState,
 	T_UniqueState,
 	T_HashState,
 	T_SetOpState,
 	T_LimitState,
 	T_MotionState,
 	T_ShareInputScanState,
 	T_WindowState,
 	T_RepeatState,
 	T_DMLState,
 	T_SplitUpdateState,
 	T_RowTriggerState,
 	T_AssertOpState,
 	T_PartitionSelectorState,
 	T_MagmaIndexScanState,
 	T_MagmaIndexOnlyScanState,
 	T_MagmaBitmapScanState,
 	T_OrcIndexScanState,
 	T_OrcIndexOnlyScanState,
 	T_PlanState_End,

 	/*
 	 * TAGS FOR PRIMITIVE NODES (primnodes.h)
 	 */
 	T_Alias = 300,
 	T_RangeVar,
 	T_Expr,
 	T_Var,
 	T_Const,
 	T_Param,
 	T_Aggref,
 	T_WindowRef,
 	T_ArrayRef,
 	T_FuncExpr,
 	T_OpExpr,
 	T_DistinctExpr,
 	T_ScalarArrayOpExpr,
 	T_BoolExpr,
 	T_SubLink,
 	T_SubPlan,
 	T_FieldSelect,
 	T_FieldStore,
 	T_RelabelType,
 	T_ConvertRowtypeExpr,
 	T_CaseExpr,
 	T_CaseWhen,
 	T_CaseTestExpr,
 	T_ArrayExpr,
 	T_RowExpr,
 	T_RowCompareExpr,
 	T_CoalesceExpr,
 	T_MinMaxExpr,
 	T_NullIfExpr,
 	T_NullTest,
 	T_BooleanTest,
 	T_CoerceToDomain,
 	T_CoerceToDomainValue,
 	T_SetToDefault,
 	T_CurrentOfExpr,
 	T_TargetEntry,
 	T_RangeTblRef,
 	T_JoinExpr,
 	T_FromExpr,
 	T_Flow,
 	T_WindowFrame,
 	T_WindowFrameEdge,
 	T_WindowKey,
 	T_Grouping,
 	T_GroupId,
 	T_IntoClause,
   T_AggOrder,
 	T_PercentileExpr,
 	T_DMLActionExpr,
 	T_PartOidExpr,
 	T_PartDefaultExpr,
 	T_PartBoundExpr,
 	T_PartBoundInclusionExpr,
 	T_PartBoundOpenExpr,
 	T_GraphEntry,

 	/*
 	 * TAGS FOR EXPRESSION STATE NODES (execnodes.h)
 	 *
 	 * These correspond (not always one-for-one) to primitive nodes derived
 	 * from Expr.
 	 */
 	T_ExprState = 400,
 	T_GenericExprState,
 	T_AggrefExprState,
 	T_ArrayRefExprState,
 	T_FuncExprState,
 	T_ScalarArrayOpExprState,
 	T_BoolExprState,
 	T_SubPlanState,
 	T_FieldSelectState,
 	T_FieldStoreState,
 	T_ConvertRowtypeExprState,
 	T_CaseExprState,
 	T_CaseWhenState,
 	T_ArrayExprState,
 	T_RowExprState,
 	T_RowCompareExprState,
 	T_CoalesceExprState,
 	T_MinMaxExprState,
 	T_NullTestState,
 	T_CoerceToDomainState,
 	T_DomainConstraintState,
 	T_WindowRefExprState,
 	T_GroupingFuncExprState,
 	T_PercentileExprState,
 	T_PartOidExprState,
 	T_PartDefaultExprState,
 	T_PartBoundExprState,
 	T_PartBoundInclusionExprState,
 	T_PartBoundOpenExprState,

 	/*
 	 * TAGS FOR PLANNER NODES (relation.h)
 	 */
 	T_PlannerInfo = 500,
 	T_PlannerGlobal,
 	T_RelOptInfo,
 	T_IndexOptInfo,
 	T_Path,
 	T_AppendOnlyPath,
 	T_ParquetPath,
 	T_ExternalPath,
 	T_IndexPath,
 	T_BitmapHeapPath,
 	T_BitmapAppendOnlyPath,
 	T_BitmapTableScanPath,
 	T_BitmapAndPath,
 	T_BitmapOrPath,
 	T_NestPath,
 	T_MergePath,
 	T_HashPath,
 	T_TidPath,
 	T_AppendPath,
 	T_ResultPath,
 	T_MaterialPath,
 	T_UniquePath,
 	T_MagmaIndexPath,
 	T_MagmaIndexOnlyScanPath,
 	T_MagmaBitmapScanPath,
 	T_CtePath,
 	T_PathKeyItem,
 	T_RestrictInfo,
 	T_InnerIndexscanInfo,
 	T_OuterJoinInfo,
 	T_InClauseInfo,
 	T_AppendRelInfo,
 	T_Partition,
 	T_PartitionRule,
 	T_PartitionNode,
 	T_PgPartRule,
 	T_SegfileMapNode,
 	T_FileSplitNode,
 	T_SegFileSplitMapNode,
 	T_ResultRelSegFileInfo,
 	T_ResultRelSegFileInfoMapNode,
 	T_VirtualSegmentNode,
 	T_PlannerParamItem,
 	T_NativeOrcIndexFile,

     /* Tags for MPP planner nodes (relation.h) */
     T_CdbMotionPath = 580,
     T_CdbRelDedupInfo,
     T_CdbRelColumnInfo,

 		T_Split_Block,

 	/*
 	 * TAGS FOR MEMORY NODES (memnodes.h)
 	 */
 	T_MemoryContext = 600,
 	T_AllocSetContext,
 	T_MPoolContext,
 	T_MemoryAccount,
 	T_SerializedMemoryAccount,

     T_AsetDirectContext = 610,                                      /*CDB*/

 	/*
 	 * TAGS FOR VALUE NODES (value.h)
 	 */
 	T_Value = 650,
 	T_Integer,
 	T_Float,
 	T_String,
 	T_BitString,
 	T_Null,

 	/*
 	 * TAGS FOR LIST NODES (pg_list.h)
 	 */
 	T_List,
 	T_IntList,
 	T_OidList,

 	/*
 	 * TAGS FOR PARSE TREE NODES (parsenodes.h)
 	 */
 	T_Query = 700,
 	T_PlannedStmt,
 	T_InsertStmt,
 	T_DeleteStmt,
 	T_UpdateStmt,
 	T_SelectStmt,
 	T_AlterTableStmt,
 	T_AlterTableCmd,
 	T_AlterDomainStmt,
 	T_SetOperationStmt,
 	T_GrantStmt,
 	T_GrantRoleStmt,
 	T_ClosePortalStmt,
 	T_ClusterStmt,
 	T_CopyStmt,
 	T_CreateStmt,
 	T_SingleRowErrorDesc,
 	T_ExtTableTypeDesc,
 	T_CreateExternalStmt,
 	T_DefineStmt,
 	T_DropStmt,
 	T_TruncateStmt,
 	T_CommentStmt,
 	T_FetchStmt,
 	T_IndexStmt,
 	T_CreateFunctionStmt,
 	T_AlterFunctionStmt,
 	T_RemoveFuncStmt,
 	T_RenameStmt,
 	T_RuleStmt,
 	T_NotifyStmt,
 	T_ListenStmt,
 	T_UnlistenStmt,
 	T_TransactionStmt,
 	T_ViewStmt,
 	T_LoadStmt,
 	T_CreateDomainStmt,
 	T_CreatedbStmt,
 	T_DropdbStmt,
 	T_VacuumStmt,
 	T_ExplainStmt,
 	T_CreateSeqStmt,
 	T_AlterSeqStmt,
 	T_VariableSetStmt,
 	T_VariableShowStmt,
 	T_VariableResetStmt,
 	T_CreateTrigStmt,
 	T_DropPropertyStmt,
 	T_CreatePLangStmt,
 	T_DropPLangStmt,
 	T_CreateRoleStmt,
 	T_AlterRoleStmt,
 	T_DropRoleStmt,
 	T_CreateQueueStmt,
 	T_AlterQueueStmt,
 	T_DropQueueStmt,
 	T_LockStmt,
 	T_ConstraintsSetStmt,
 	T_ReindexStmt,
 	T_CheckPointStmt,
 	T_CreateSchemaStmt,
 	T_AlterDatabaseStmt,
 	T_AlterDatabaseSetStmt,
 	T_AlterRoleSetStmt,
 	T_CreateConversionStmt,
 	T_CreateCastStmt,
 	T_DropCastStmt,
 	T_CreateOpClassStmt,
 	T_RemoveOpClassStmt,
 	T_PrepareStmt,
 	T_ExecuteStmt,
 	T_DeallocateStmt,
 	T_DeclareCursorStmt,
 	T_CreateTableSpaceStmt,
 	T_DropTableSpaceStmt,           /* Removed, See DropStmt */
 	T_AlterObjectSchemaStmt,
 	T_AlterOwnerStmt,
 	T_DropOwnedStmt,
 	T_ReassignOwnedStmt,
 	T_WindowSpec,
 	T_WindowSpecParse,
 	T_PartitionBy,
 	T_PartitionElem,
 	T_PartitionRangeItem,
 	T_PartitionBoundSpec,
 	T_PartitionSpec,
 	T_PartitionValuesSpec,
 	T_AlterPartitionId,
 	T_AlterPartitionCmd,
 	T_InheritPartitionCmd,
 	T_CreateFileSpaceStmt,
 	T_CreateFdwStmt,
 	T_AlterFdwStmt,
 	T_DropFdwStmt,
 	T_CreateForeignServerStmt,
 	T_AlterForeignServerStmt,
 	T_DropForeignServerStmt,
 	T_CreateUserMappingStmt,
 	T_AlterUserMappingStmt,
 	T_DropUserMappingStmt,
 	T_CreateForeignStmt,
 	T_TableValueExpr,
 	T_DenyLoginInterval,
 	T_DenyLoginPoint,
 	T_AlterTypeStmt,
 	T_AlterRewriteTableInfo,
 	T_AlterRewriteNewConstraint,
 	T_AlterRewriteNewColumnValue,
 	T_SharedStorageOpStmt,
 	T_CreateVlabelStmt,
 	T_CreateElabelStmt,
 	T_CreateGraphStmt,
 	/**/

 	T_A_Expr = 850,
 	T_ColumnRef,
 	T_ParamRef,
 	T_A_Const,
 	T_FuncCall,
 	T_A_Indices,
 	T_A_Indirection,
 	T_ResTarget,
 	T_TypeCast,
 	T_SortBy,
 	T_RangeSubselect,
 	T_RangeFunction,
 	T_TypeName,
 	T_ColumnDef,
 	T_IndexElem,
 	T_Constraint,
 	T_DefElem,
 	T_RangeTblEntry,
 	T_SortClause,
 	T_GroupClause,
 	T_GroupingClause,
 	T_GroupingFunc,
 	T_FkConstraint,
 	T_PrivGrantee,
 	T_FuncWithArgs,
 	T_PrivTarget,
 	T_CreateOpClassItem,
 	T_CompositeTypeStmt,
 	T_InhRelation,
 	T_FunctionParameter,
 	T_LockingClause,
 	T_RowMarkClause,
 	T_WithClause,
 	T_CommonTableExpr,
 	T_ColumnReferenceStorageDirective,

 	/*
 	 * TAGS FOR RANDOM OTHER STUFF
 	 *
 	 * These are objects that aren't part of parse/plan/execute node tree
 	 * structures, but we give them NodeTags anyway for identification
 	 * purposes (usually because they are involved in APIs where we want to
 	 * pass multiple object types through the same pointer).
 	 */
 	T_TriggerData = 900,		    /* in commands/trigger.h */
 	T_ReturnSetInfo,			    /* in nodes/execnodes.h */
 	T_HashBitmap,                   /* in nodes/tidbitmap.h */
 	T_StreamBitmap,                 /* in nodes/tidbitmap.h */
 	T_FormatterData,                /* in access/formatter.h */
 	T_ExtProtocolData,              /* in access/extprotocol.h */
 	T_ExtProtocolValidatorData,     /* in access/extprotocol.h */
 	T_ExtProtocolRenameData,
 	T_PlugStorageData,              /* in access/plugstorage.h */
 	T_PlugStorageTransactionData,   /* in access/plugstorage.h */
 	T_PlugStorageValidatorData,     /* in access/plugstorage.h */
 	T_FileSystemFunctionData,       /* in storage/filesystem.h */
 	T_PartitionConstraints,         /* in executor/nodePartitionSelector.h */
 	T_SelectedParts,                /* in executor/nodePartitionSelector.h */
 	T_ExtProtocolBlockLocationData, /* in access/extprotocol.h */
 	T_ExtProtocolTableSizeData,     /* in access/extprotocol.h */
 	T_ExtProtocolDatabaseSizeData,  /* in access/extprotocol.h */
 	T_ExtProtocolMagmaStatusData,   /* in access/extprotocol.h */

 	/* CDB: tags for random other stuff */
 	T_CdbExplain_StatHdr = 950,             /* in cdb/cdbexplain.c */

 	/* gpsql: tags for query context dispatching */
 	T_QueryContextInfo = 1000,

 	/* tags for describing the query resource should occupied in segment*/
 	T_QueryResource = 1050,

 	/*
 	 * TAGS FOR CAQL PARSER
 	 */
 	T_CaQLSelect = 2000,
 	T_CaQLInsert,
 	T_CaQLDelete,
 	T_CaQLExpr,
 } NodeTag;

 /*
  * The first field of a node of any type is guaranteed to be the NodeTag.
  * Hence the type of any node can be gotten by casting it to Node. Declaring
  * a variable to be of Node * (instead of void *) can also facilitate
  * debugging.
  */
 typedef struct Node
 {
 	NodeTag		type;
 } Node;

 #define nodeTag(nodeptr)		(((Node*)(nodeptr))->type)

 /*
  * newNode -
  *	  create a new node of the specified size and tag the node with the
  *	  specified tag.
  *
  * !WARNING!: Avoid using newNode directly. You should be using the
  *	  macro makeNode.  eg. to create a Query node, use makeNode(Query)
  *
  * Note: the size argument should always be a compile-time constant, so the
  * apparent risk of multiple evaluation doesn't matter in practice.
  */
 #ifdef __GNUC__

 /* With GCC, we can use a compound statement within an expression */
 #define newNode(size, tag) \
 ({	Node   *_result; \
 	AssertMacro((size) >= sizeof(Node));		/* need the tag, at least */ \
 	_result = (Node *) palloc0fast(size); \
 	_result->type = (tag); \
 	_result; \
 })
 #else

 /*
  *	There is no way to dereference the palloc'ed pointer to assign the
  *	tag, and also return the pointer itself, so we need a holder variable.
  *	Fortunately, this macro isn't recursive so we just define
  *	a global variable for this purpose.
  */
 extern PGDLLIMPORT Node *newNodeMacroHolder;

 #define newNode(size, tag) \
 ( \
 	AssertMacro((size) >= sizeof(Node)),		/* need the tag, at least */ \
 	newNodeMacroHolder = (Node *) palloc0fast(size), \
 	newNodeMacroHolder->type = (tag), \
 	newNodeMacroHolder \
 )
 #endif   /* __GNUC__ */


 #define makeNode(_type_) 		((_type_ *) newNode(sizeof(_type_),T_##_type_))
 #define NodeSetTag(nodeptr,t)	(((Node*)(nodeptr))->type = (t))

 #define IsA(nodeptr,_type_)		(nodeTag(nodeptr) == T_##_type_)

 /* ----------------------------------------------------------------
  *					  extern declarations follow
  * ----------------------------------------------------------------
  */

 /*
  * nodes/{outfuncs.c,print.c}
  */
 extern char *nodeToString(void *obj);

 /*
  * nodes/outfast.c. This special version of nodeToString is only used by serializeNode.
  * It's a quick hack that allocates 8K buffer for StringInfo struct through initStringIinfoSizeOf
  */
 extern char *nodeToBinaryStringFast(void *obj, int * size);

 extern Node *readNodeFromBinaryString(const char *str, int len);
 /*
  * nodes/{readfuncs.c,read.c}
  */
 extern void *stringToNode(char *str);

 /*
  * nodes/copyfuncs.c
  */
 extern void *copyObject(void *obj);

 /*
  * nodes/equalfuncs.c
  */
 extern bool equal(void *a, void *b);


 /*
  * Typedefs for identifying qualifier selectivities and plan costs as such.
  * These are just plain "double"s, but declaring a variable as Selectivity
  * or Cost makes the intent more obvious.
  *
  * These could have gone into plannodes.h or some such, but many files
  * depend on them...
  */
 typedef double Selectivity;		/* fraction of tuples a qualifier will pass */
 typedef double Cost;			/* execution cost (in page-access units) */


 /*
  * CmdType -
  *	  enums for type of operation represented by a Query
  *
  * ??? could have put this in parsenodes.h but many files not in the
  *	  optimizer also need this...
  */
 typedef enum CmdType
 {
 	CMD_UNKNOWN,
 	CMD_SELECT,					/* select stmt */
 	CMD_UPDATE,					/* update stmt */
 	CMD_INSERT,					/* insert stmt */
 	CMD_DELETE,
 	CMD_UTILITY,				/* cmds like create, destroy, copy, vacuum,
 								 * etc. */
 	CMD_NOTHING					/* dummy command for instead nothing rules
 								 * with qual */
 } CmdType;


 /*
  * JoinType -
  *	  enums for types of relation joins
  *
  * JoinType determines the exact semantics of joining two relations using
  * a matching qualification.  For example, it tells what to do with a tuple
  * that has no match in the other relation.
  *
  * This is needed in both parsenodes.h and plannodes.h, so put it here...
  */
 typedef enum JoinType
 {
 	/*
 	 * The canonical kinds of joins according to the SQL JOIN syntax. Only
 	 * these codes can appear in parser output (e.g., JoinExpr nodes).
 	 */
 	JOIN_INNER,					/* matching tuple pairs only */
 	JOIN_LEFT,					/* pairs + unmatched LHS tuples */
 	JOIN_FULL,					/* pairs + unmatched LHS + unmatched RHS */
 	JOIN_RIGHT,					/* pairs + unmatched RHS tuples */

 	/*
 	 * These are used for queries like WHERE foo IN (SELECT bar FROM ...).
 	 * Only JOIN_IN is actually implemented in the executor; the others are
 	 * defined for internal use in the planner.
      *
      * CDB: We no longer use JOIN_REVERSE_IN, JOIN_UNIQUE_OUTER or
      * JOIN_UNIQUE_INNER.  The definitions are retained in case they
      * might be referenced in the source code of user-defined
      * selectivity functions brought over from PostgreSQL.
 	 */
 	JOIN_IN,					/* at most one result per outer row */
 	JOIN_REVERSE_IN,			/* at most one result per inner row */
 	JOIN_UNIQUE_OUTER,			/* outer path must be made unique */
 	JOIN_UNIQUE_INNER,			/* inner path must be made unique */
 	JOIN_LASJ,					/* Left Anti Semi Join:
 								   one copy of outer row with no match in inner */
 	JOIN_LASJ_NOTIN				/* Left Anti Semi Join with Not-In semantics:
 									If any NULL values are produced by inner side,
 									return no join results. Otherwise, same as LASJ */

 	/*
 	 * We might need additional join types someday.
 	 */
 } JoinType;

 #define IS_OUTER_JOIN(jointype) \
 	((jointype) == JOIN_LEFT || \
 	 (jointype) == JOIN_FULL || \
 	 (jointype) == JOIN_RIGHT)


 /*
  * FlowType - kinds of tuple flows in parallelized plans.
  *
  * This enum is a MPP extension.
  */
 typedef enum FlowType
 {
 	FLOW_UNDEFINED,		/* used prior to calculation of type of derived flow */
 	FLOW_SINGLETON,		/* flow has single stream */
 	FLOW_REPLICATED,	/* flow is replicated across IOPs */
 	FLOW_PARTITIONED,	/* flow is partitioned across IOPs */
 } FlowType;

 /*
  * DispatchMethod - MPP dispatch method.
  *
  * There are currently three possibilties, an initial value of undetermined,
  * and a value for each of the ways the dispatch code implements.
  */
 typedef enum DispatchMethod
 {
 	DISPATCH_UNDETERMINED = 0,	/* Used prior to determination. */
 	DISPATCH_SEQUENTIAL,		/* Dispatch on entry postgres process only. */
 	DISPATCH_PARALLEL			/* Dispatch on query executor and entry processes. */

 } DispatchMethod;

 /*
  * Inside the executor, if a caller to some data type manipulation functions
  * (e.g., int8inc()) is doing aggregate or window function work, we want to
  * avoid copying the input datum and just write directly over the input. This
  * isn't legal if the function is being used outside this context.
  */
 #define IS_AGG_EXECUTION_NODE(node) \
 	((IsA((Node *)(node), AggState) || IsA((Node *)(node), WindowState)) ? \
 	 true : false)

 /*
  * If the partIndex in Scan set to 0 then we don't have
  * any dynamic partition scanning
  */
 #define INVALID_PART_INDEX 0

 #endif   /* NODES_H */
	/*
	* 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,
	* 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.
	*/

	/*-------------------------------------------------------------------------
	*
	* nodes.h
	* Definitions for tagged nodes.
	*
	*
	* Portions Copyright (c) 2005-2009, Greenplum inc
	* Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
	* Portions Copyright (c) 1994, Regents of the University of California
	*
	* $PostgreSQL: pgsql/src/include/nodes/nodes.h,v 1.188 2006/09/28 20:51:42 tgl Exp $
	*
	*-------------------------------------------------------------------------
	*/
	#ifndef NODES_H
	#define NODES_H

	/*
	* The first field of every node is NodeTag. Each node created (with makeNode)
	* will have one of the following tags as the value of its first field.
	*
	* Note that the numbers of the node tags are not contiguous. We left holes
	* here so that we can add more tags without changing the existing enum's.
	* (Since node tag numbers never exist outside backend memory, there's no
	* real harm in renumbering, it just costs a full rebuild ...)
	*/
	typedef enum NodeTag
	{
	T_Invalid = 0,

	/*
	* TAGS FOR EXECUTOR NODES (execnodes.h)
	*/
	T_IndexInfo = 10,
	T_ExprContext,
	T_ProjectionInfo,
	T_JunkFilter,
	T_ResultRelInfo,
	T_EState,
	T_TupleTableSlot,
	T_CdbProcess,
	T_Slice,
	T_SliceTable,
	T_ShareNodeEntry,
	T_PartitionState,

	/*
	* TAGS FOR PLAN NODES (plannodes.h)
	*/
	T_Plan = 100,
	T_Scan,
	T_Join,
	T_CteScan,

	/* Real plan node starts below. Scan and Join are "Virtal nodes",
	* It will take the form of IndexScan, SeqScan, etc.
	* CteScan will take the form of SubqueryScan.
	*/
	T_Result,
	T_Plan_Start = T_Result,
	T_Append,
	T_Sequence,
	T_BitmapAnd,
	T_BitmapOr,
	T_SeqScan,
	T_ExternalScan,
	T_AppendOnlyScan,
	T_TableScan,
	T_DynamicTableScan,
	T_ParquetScan,
	T_IndexScan,
	T_DynamicIndexScan,
	T_BitmapIndexScan,
	T_BitmapHeapScan,
	T_BitmapTableScan,
	T_TidScan,
	T_SubqueryScan,
	T_FunctionScan,
	T_TableFunctionScan,
	T_ValuesScan,
	T_NestLoop,
	T_MergeJoin,
	T_HashJoin,
	T_Material,
	T_Sort,
	T_Agg,
	T_Unique,
	T_Hash,
	T_SetOp,
	T_Limit,
	T_Motion,
	T_ShareInputScan,
	T_Window,
	T_Repeat,
	T_DML,
	T_SplitUpdate,
	T_RowTrigger,
	T_AssertOp,
	T_PartitionSelector,
	T_MagmaIndexScan,
	T_MagmaIndexOnlyScan,
	T_MagmaBitmapScan,
	T_OrcIndexScan,
	T_OrcIndexOnlyScan,
	T_Plan_End,
	/* this one isn't a subclass of Plan: */
	T_PlanInvalItem,

	/*
	* TAGS FOR PLAN STATE NODES (execnodes.h)
	*
	* These should correspond one-to-one with Plan node types.
	*/
	T_PlanState = 200,
	T_ScanState,
	T_JoinState,

	/* Real plan node starts below. Scan and Join are "Virtal nodes",
	* It will take the form of IndexScan, SeqScan, etc.
	*/
	T_ResultState,
	T_PlanState_Start = T_ResultState,
	T_AppendState,
	T_SequenceState,
	T_BitmapAndState,
	T_BitmapOrState,
	T_SeqScanState,
	T_AppendOnlyScanState,
	T_ParquetScanState,
	T_TableScanState,
	T_DynamicTableScanState,
	T_ExternalScanState,
	T_IndexScanState,
	T_DynamicIndexScanState,
	T_BitmapIndexScanState,
	T_BitmapHeapScanState,
	T_BitmapTableScanState,
	T_TidScanState,
	T_SubqueryScanState,
	T_FunctionScanState,
	T_TableFunctionState,
	T_ValuesScanState,
	T_NestLoopState,
	T_MergeJoinState,
	T_HashJoinState,
	T_MaterialState,
	T_SortState,
	T_AggState,
	T_UniqueState,
	T_HashState,
	T_SetOpState,
	T_LimitState,
	T_MotionState,
	T_ShareInputScanState,
	T_WindowState,
	T_RepeatState,
	T_DMLState,
	T_SplitUpdateState,
	T_RowTriggerState,
	T_AssertOpState,
	T_PartitionSelectorState,
	T_MagmaIndexScanState,
	T_MagmaIndexOnlyScanState,
	T_MagmaBitmapScanState,
	T_OrcIndexScanState,
	T_OrcIndexOnlyScanState,
	T_PlanState_End,

	/*
	* TAGS FOR PRIMITIVE NODES (primnodes.h)
	*/
	T_Alias = 300,
	T_RangeVar,
	T_Expr,
	T_Var,
	T_Const,
	T_Param,
	T_Aggref,
	T_WindowRef,
	T_ArrayRef,
	T_FuncExpr,
	T_OpExpr,
	T_DistinctExpr,
	T_ScalarArrayOpExpr,
	T_BoolExpr,
	T_SubLink,
	T_SubPlan,
	T_FieldSelect,
	T_FieldStore,
	T_RelabelType,
	T_ConvertRowtypeExpr,
	T_CaseExpr,
	T_CaseWhen,
	T_CaseTestExpr,
	T_ArrayExpr,
	T_RowExpr,
	T_RowCompareExpr,
	T_CoalesceExpr,
	T_MinMaxExpr,
	T_NullIfExpr,
	T_NullTest,
	T_BooleanTest,
	T_CoerceToDomain,
	T_CoerceToDomainValue,
	T_SetToDefault,
	T_CurrentOfExpr,
	T_TargetEntry,
	T_RangeTblRef,
	T_JoinExpr,
	T_FromExpr,
	T_Flow,
	T_WindowFrame,
	T_WindowFrameEdge,
	T_WindowKey,
	T_Grouping,
	T_GroupId,
	T_IntoClause,
	T_AggOrder,
	T_PercentileExpr,
	T_DMLActionExpr,
	T_PartOidExpr,
	T_PartDefaultExpr,
	T_PartBoundExpr,
	T_PartBoundInclusionExpr,
	T_PartBoundOpenExpr,
	T_GraphEntry,

	/*
	* TAGS FOR EXPRESSION STATE NODES (execnodes.h)
	*
	* These correspond (not always one-for-one) to primitive nodes derived
	* from Expr.
	*/
	T_ExprState = 400,
	T_GenericExprState,
	T_AggrefExprState,
	T_ArrayRefExprState,
	T_FuncExprState,
	T_ScalarArrayOpExprState,
	T_BoolExprState,
	T_SubPlanState,
	T_FieldSelectState,
	T_FieldStoreState,
	T_ConvertRowtypeExprState,
	T_CaseExprState,
	T_CaseWhenState,
	T_ArrayExprState,
	T_RowExprState,
	T_RowCompareExprState,
	T_CoalesceExprState,
	T_MinMaxExprState,
	T_NullTestState,
	T_CoerceToDomainState,
	T_DomainConstraintState,
	T_WindowRefExprState,
	T_GroupingFuncExprState,
	T_PercentileExprState,
	T_PartOidExprState,
	T_PartDefaultExprState,
	T_PartBoundExprState,
	T_PartBoundInclusionExprState,
	T_PartBoundOpenExprState,

	/*
	* TAGS FOR PLANNER NODES (relation.h)
	*/
	T_PlannerInfo = 500,
	T_PlannerGlobal,
	T_RelOptInfo,
	T_IndexOptInfo,
	T_Path,
	T_AppendOnlyPath,
	T_ParquetPath,
	T_ExternalPath,
	T_IndexPath,
	T_BitmapHeapPath,
	T_BitmapAppendOnlyPath,
	T_BitmapTableScanPath,
	T_BitmapAndPath,
	T_BitmapOrPath,
	T_NestPath,
	T_MergePath,
	T_HashPath,
	T_TidPath,
	T_AppendPath,
	T_ResultPath,
	T_MaterialPath,
	T_UniquePath,
	T_MagmaIndexPath,
	T_MagmaIndexOnlyScanPath,
	T_MagmaBitmapScanPath,
	T_CtePath,
	T_PathKeyItem,
	T_RestrictInfo,
	T_InnerIndexscanInfo,
	T_OuterJoinInfo,
	T_InClauseInfo,
	T_AppendRelInfo,
	T_Partition,
	T_PartitionRule,
	T_PartitionNode,
	T_PgPartRule,
	T_SegfileMapNode,
	T_FileSplitNode,
	T_SegFileSplitMapNode,
	T_ResultRelSegFileInfo,
	T_ResultRelSegFileInfoMapNode,
	T_VirtualSegmentNode,
	T_PlannerParamItem,
	T_NativeOrcIndexFile,

	/* Tags for MPP planner nodes (relation.h) */
	T_CdbMotionPath = 580,
	T_CdbRelDedupInfo,
	T_CdbRelColumnInfo,

	T_Split_Block,

	/*
	* TAGS FOR MEMORY NODES (memnodes.h)
	*/
	T_MemoryContext = 600,
	T_AllocSetContext,
	T_MPoolContext,
	T_MemoryAccount,
	T_SerializedMemoryAccount,

	T_AsetDirectContext = 610, /CDB/

	/*
	* TAGS FOR VALUE NODES (value.h)
	*/
	T_Value = 650,
	T_Integer,
	T_Float,
	T_String,
	T_BitString,
	T_Null,

	/*
	* TAGS FOR LIST NODES (pg_list.h)
	*/
	T_List,
	T_IntList,
	T_OidList,

	/*
	* TAGS FOR PARSE TREE NODES (parsenodes.h)
	*/
	T_Query = 700,
	T_PlannedStmt,
	T_InsertStmt,
	T_DeleteStmt,
	T_UpdateStmt,
	T_SelectStmt,
	T_AlterTableStmt,
	T_AlterTableCmd,
	T_AlterDomainStmt,
	T_SetOperationStmt,
	T_GrantStmt,
	T_GrantRoleStmt,
	T_ClosePortalStmt,
	T_ClusterStmt,
	T_CopyStmt,
	T_CreateStmt,
	T_SingleRowErrorDesc,
	T_ExtTableTypeDesc,
	T_CreateExternalStmt,
	T_DefineStmt,
	T_DropStmt,
	T_TruncateStmt,
	T_CommentStmt,
	T_FetchStmt,
	T_IndexStmt,
	T_CreateFunctionStmt,
	T_AlterFunctionStmt,
	T_RemoveFuncStmt,
	T_RenameStmt,
	T_RuleStmt,
	T_NotifyStmt,
	T_ListenStmt,
	T_UnlistenStmt,
	T_TransactionStmt,
	T_ViewStmt,
	T_LoadStmt,
	T_CreateDomainStmt,
	T_CreatedbStmt,
	T_DropdbStmt,
	T_VacuumStmt,
	T_ExplainStmt,
	T_CreateSeqStmt,
	T_AlterSeqStmt,
	T_VariableSetStmt,
	T_VariableShowStmt,
	T_VariableResetStmt,
	T_CreateTrigStmt,
	T_DropPropertyStmt,
	T_CreatePLangStmt,
	T_DropPLangStmt,
	T_CreateRoleStmt,
	T_AlterRoleStmt,
	T_DropRoleStmt,
	T_CreateQueueStmt,
	T_AlterQueueStmt,
	T_DropQueueStmt,
	T_LockStmt,
	T_ConstraintsSetStmt,
	T_ReindexStmt,
	T_CheckPointStmt,
	T_CreateSchemaStmt,
	T_AlterDatabaseStmt,
	T_AlterDatabaseSetStmt,
	T_AlterRoleSetStmt,
	T_CreateConversionStmt,
	T_CreateCastStmt,
	T_DropCastStmt,
	T_CreateOpClassStmt,
	T_RemoveOpClassStmt,
	T_PrepareStmt,
	T_ExecuteStmt,
	T_DeallocateStmt,
	T_DeclareCursorStmt,
	T_CreateTableSpaceStmt,
	T_DropTableSpaceStmt, /* Removed, See DropStmt */
	T_AlterObjectSchemaStmt,
	T_AlterOwnerStmt,
	T_DropOwnedStmt,
	T_ReassignOwnedStmt,
	T_WindowSpec,
	T_WindowSpecParse,
	T_PartitionBy,
	T_PartitionElem,
	T_PartitionRangeItem,
	T_PartitionBoundSpec,
	T_PartitionSpec,
	T_PartitionValuesSpec,
	T_AlterPartitionId,
	T_AlterPartitionCmd,
	T_InheritPartitionCmd,
	T_CreateFileSpaceStmt,
	T_CreateFdwStmt,
	T_AlterFdwStmt,
	T_DropFdwStmt,
	T_CreateForeignServerStmt,
	T_AlterForeignServerStmt,
	T_DropForeignServerStmt,
	T_CreateUserMappingStmt,
	T_AlterUserMappingStmt,
	T_DropUserMappingStmt,
	T_CreateForeignStmt,
	T_TableValueExpr,
	T_DenyLoginInterval,
	T_DenyLoginPoint,
	T_AlterTypeStmt,
	T_AlterRewriteTableInfo,
	T_AlterRewriteNewConstraint,
	T_AlterRewriteNewColumnValue,
	T_SharedStorageOpStmt,
	T_CreateVlabelStmt,
	T_CreateElabelStmt,
	T_CreateGraphStmt,
	/**/

	T_A_Expr = 850,
	T_ColumnRef,
	T_ParamRef,
	T_A_Const,
	T_FuncCall,
	T_A_Indices,
	T_A_Indirection,
	T_ResTarget,
	T_TypeCast,
	T_SortBy,
	T_RangeSubselect,
	T_RangeFunction,
	T_TypeName,
	T_ColumnDef,
	T_IndexElem,
	T_Constraint,
	T_DefElem,
	T_RangeTblEntry,
	T_SortClause,
	T_GroupClause,
	T_GroupingClause,
	T_GroupingFunc,
	T_FkConstraint,
	T_PrivGrantee,
	T_FuncWithArgs,
	T_PrivTarget,
	T_CreateOpClassItem,
	T_CompositeTypeStmt,
	T_InhRelation,
	T_FunctionParameter,
	T_LockingClause,
	T_RowMarkClause,
	T_WithClause,
	T_CommonTableExpr,
	T_ColumnReferenceStorageDirective,

	/*
	* TAGS FOR RANDOM OTHER STUFF
	*
	* These are objects that aren't part of parse/plan/execute node tree
	* structures, but we give them NodeTags anyway for identification
	* purposes (usually because they are involved in APIs where we want to
	* pass multiple object types through the same pointer).
	*/
	T_TriggerData = 900, /* in commands/trigger.h */
	T_ReturnSetInfo, /* in nodes/execnodes.h */
	T_HashBitmap, /* in nodes/tidbitmap.h */
	T_StreamBitmap, /* in nodes/tidbitmap.h */
	T_FormatterData, /* in access/formatter.h */
	T_ExtProtocolData, /* in access/extprotocol.h */
	T_ExtProtocolValidatorData, /* in access/extprotocol.h */
	T_ExtProtocolRenameData,
	T_PlugStorageData, /* in access/plugstorage.h */
	T_PlugStorageTransactionData, /* in access/plugstorage.h */
	T_PlugStorageValidatorData, /* in access/plugstorage.h */
	T_FileSystemFunctionData, /* in storage/filesystem.h */
	T_PartitionConstraints, /* in executor/nodePartitionSelector.h */
	T_SelectedParts, /* in executor/nodePartitionSelector.h */
	T_ExtProtocolBlockLocationData, /* in access/extprotocol.h */
	T_ExtProtocolTableSizeData, /* in access/extprotocol.h */
	T_ExtProtocolDatabaseSizeData, /* in access/extprotocol.h */
	T_ExtProtocolMagmaStatusData, /* in access/extprotocol.h */

	/* CDB: tags for random other stuff */
	T_CdbExplain_StatHdr = 950, /* in cdb/cdbexplain.c */

	/* gpsql: tags for query context dispatching */
	T_QueryContextInfo = 1000,

	/* tags for describing the query resource should occupied in segment*/
	T_QueryResource = 1050,

	/*
	* TAGS FOR CAQL PARSER
	*/
	T_CaQLSelect = 2000,
	T_CaQLInsert,
	T_CaQLDelete,
	T_CaQLExpr,
	} NodeTag;

	/*
	* The first field of a node of any type is guaranteed to be the NodeTag.
	* Hence the type of any node can be gotten by casting it to Node. Declaring
	* a variable to be of Node * (instead of void *) can also facilitate
	* debugging.
	*/
	typedef struct Node
	{
	NodeTag type;
	} Node;

	#define nodeTag(nodeptr) (((Node*)(nodeptr))->type)

	/*
	* newNode -
	* create a new node of the specified size and tag the node with the
	* specified tag.
	*
	* !WARNING!: Avoid using newNode directly. You should be using the
	* macro makeNode. eg. to create a Query node, use makeNode(Query)
	*
	* Note: the size argument should always be a compile-time constant, so the
	* apparent risk of multiple evaluation doesn't matter in practice.
	*/
	#ifdef __GNUC__

	/* With GCC, we can use a compound statement within an expression */
	#define newNode(size, tag) \
	({ Node *_result; \
	AssertMacro((size) >= sizeof(Node)); /* need the tag, at least */ \
	_result = (Node *) palloc0fast(size); \
	_result->type = (tag); \
	_result; \
	})
	#else

	/*
	* There is no way to dereference the palloc'ed pointer to assign the
	* tag, and also return the pointer itself, so we need a holder variable.
	* Fortunately, this macro isn't recursive so we just define
	* a global variable for this purpose.
	*/
	extern PGDLLIMPORT Node *newNodeMacroHolder;

	#define newNode(size, tag) \
	( \
	AssertMacro((size) >= sizeof(Node)), /* need the tag, at least */ \
	newNodeMacroHolder = (Node *) palloc0fast(size), \
	newNodeMacroHolder->type = (tag), \
	newNodeMacroHolder \
	)
	#endif /* __GNUC__ */


	#define makeNode(_type_) ((_type_ *) newNode(sizeof(_type_),T_##_type_))
	#define NodeSetTag(nodeptr,t) (((Node*)(nodeptr))->type = (t))

	#define IsA(nodeptr,_type_) (nodeTag(nodeptr) == T_##_type_)

	/* ----------------------------------------------------------------
	* extern declarations follow
	* ----------------------------------------------------------------
	*/

	/*
	* nodes/{outfuncs.c,print.c}
	*/
	extern char nodeToString(void obj);

	/*
	* nodes/outfast.c. This special version of nodeToString is only used by serializeNode.
	* It's a quick hack that allocates 8K buffer for StringInfo struct through initStringIinfoSizeOf
	*/
	extern char nodeToBinaryStringFast(void obj, int * size);

	extern Node readNodeFromBinaryString(const char str, int len);
	/*
	* nodes/{readfuncs.c,read.c}
	*/
	extern void stringToNode(char str);

	/*
	* nodes/copyfuncs.c
	*/
	extern void copyObject(void obj);

	/*
	* nodes/equalfuncs.c
	*/
	extern bool equal(void a, void b);


	/*
	* Typedefs for identifying qualifier selectivities and plan costs as such.
	* These are just plain "double"s, but declaring a variable as Selectivity
	* or Cost makes the intent more obvious.
	*
	* These could have gone into plannodes.h or some such, but many files
	* depend on them...
	*/
	typedef double Selectivity; /* fraction of tuples a qualifier will pass */
	typedef double Cost; /* execution cost (in page-access units) */


	/*
	* CmdType -
	* enums for type of operation represented by a Query
	*
	* ??? could have put this in parsenodes.h but many files not in the
	* optimizer also need this...
	*/
	typedef enum CmdType
	{
	CMD_UNKNOWN,
	CMD_SELECT, /* select stmt */
	CMD_UPDATE, /* update stmt */
	CMD_INSERT, /* insert stmt */
	CMD_DELETE,
	CMD_UTILITY, /* cmds like create, destroy, copy, vacuum,
	* etc. */
	CMD_NOTHING /* dummy command for instead nothing rules
	* with qual */
	} CmdType;


	/*
	* JoinType -
	* enums for types of relation joins
	*
	* JoinType determines the exact semantics of joining two relations using
	* a matching qualification. For example, it tells what to do with a tuple
	* that has no match in the other relation.
	*
	* This is needed in both parsenodes.h and plannodes.h, so put it here...
	*/
	typedef enum JoinType
	{
	/*
	* The canonical kinds of joins according to the SQL JOIN syntax. Only
	* these codes can appear in parser output (e.g., JoinExpr nodes).
	*/
	JOIN_INNER, /* matching tuple pairs only */
	JOIN_LEFT, /* pairs + unmatched LHS tuples */
	JOIN_FULL, /* pairs + unmatched LHS + unmatched RHS */
	JOIN_RIGHT, /* pairs + unmatched RHS tuples */

	/*
	* These are used for queries like WHERE foo IN (SELECT bar FROM ...).
	* Only JOIN_IN is actually implemented in the executor; the others are
	* defined for internal use in the planner.
	*
	* CDB: We no longer use JOIN_REVERSE_IN, JOIN_UNIQUE_OUTER or
	* JOIN_UNIQUE_INNER. The definitions are retained in case they
	* might be referenced in the source code of user-defined
	* selectivity functions brought over from PostgreSQL.
	*/
	JOIN_IN, /* at most one result per outer row */
	JOIN_REVERSE_IN, /* at most one result per inner row */
	JOIN_UNIQUE_OUTER, /* outer path must be made unique */
	JOIN_UNIQUE_INNER, /* inner path must be made unique */
	JOIN_LASJ, /* Left Anti Semi Join:
	one copy of outer row with no match in inner */
	JOIN_LASJ_NOTIN /* Left Anti Semi Join with Not-In semantics:
	If any NULL values are produced by inner side,
	return no join results. Otherwise, same as LASJ */

	/*
	* We might need additional join types someday.
	*/
	} JoinType;

	#define IS_OUTER_JOIN(jointype) \
	((jointype) == JOIN_LEFT \|\| \
	(jointype) == JOIN_FULL \|\| \
	(jointype) == JOIN_RIGHT)



	/*
	* FlowType - kinds of tuple flows in parallelized plans.
	*
	* This enum is a MPP extension.
	*/
	typedef enum FlowType
	{
	FLOW_UNDEFINED, /* used prior to calculation of type of derived flow */
	FLOW_SINGLETON, /* flow has single stream */
	FLOW_REPLICATED, /* flow is replicated across IOPs */
	FLOW_PARTITIONED, /* flow is partitioned across IOPs */
	} FlowType;

	/*
	* DispatchMethod - MPP dispatch method.
	*
	* There are currently three possibilties, an initial value of undetermined,
	* and a value for each of the ways the dispatch code implements.
	*/
	typedef enum DispatchMethod
	{
	DISPATCH_UNDETERMINED = 0, /* Used prior to determination. */
	DISPATCH_SEQUENTIAL, /* Dispatch on entry postgres process only. */
	DISPATCH_PARALLEL /* Dispatch on query executor and entry processes. */

	} DispatchMethod;

	/*
	* Inside the executor, if a caller to some data type manipulation functions
	* (e.g., int8inc()) is doing aggregate or window function work, we want to
	* avoid copying the input datum and just write directly over the input. This
	* isn't legal if the function is being used outside this context.
	*/
	#define IS_AGG_EXECUTION_NODE(node) \
	((IsA((Node )(node), AggState) \|\| IsA((Node )(node), WindowState)) ? \
	true : false)

	/*
	* If the partIndex in Scan set to 0 then we don't have
	* any dynamic partition scanning
	*/
	#define INVALID_PART_INDEX 0

	#endif /* NODES_H */