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f3d3118532175541a9a96ed78881a3b04a057128
postgres/src/include/nodes/nodes.h
Andres Freund f3d3118532 Support GROUPING SETS, CUBE and ROLLUP. 
This SQL standard functionality allows to aggregate data by different
GROUP BY clauses at once. Each grouping set returns rows with columns
grouped by in other sets set to NULL.

This could previously be achieved by doing each grouping as a separate
query, conjoined by UNION ALLs. Besides being considerably more concise,
grouping sets will in many cases be faster, requiring only one scan over
the underlying data.

The current implementation of grouping sets only supports using sorting
for input. Individual sets that share a sort order are computed in one
pass. If there are sets that don't share a sort order, additional sort &
aggregation steps are performed. These additional passes are sourced by
the previous sort step; thus avoiding repeated scans of the source data.

The code is structured in a way that adding support for purely using
hash aggregation or a mix of hashing and sorting is possible. Sorting
was chosen to be supported first, as it is the most generic method of
implementation.

Instead of, as in an earlier versions of the patch, representing the
chain of sort and aggregation steps as full blown planner and executor
nodes, all but the first sort are performed inside the aggregation node
itself. This avoids the need to do some unusual gymnastics to handle
having to return aggregated and non-aggregated tuples from underlying
nodes, as well as having to shut down underlying nodes early to limit
memory usage.  The optimizer still builds Sort/Agg node to describe each
phase, but they're not part of the plan tree, but instead additional
data for the aggregation node. They're a convenient and preexisting way
to describe aggregation and sorting.  The first (and possibly only) sort
step is still performed as a separate execution step. That retains
similarity with existing group by plans, makes rescans fairly simple,
avoids very deep plans (leading to slow explains) and easily allows to
avoid the sorting step if the underlying data is sorted by other means.

A somewhat ugly side of this patch is having to deal with a grammar
ambiguity between the new CUBE keyword and the cube extension/functions
named cube (and rollup). To avoid breaking existing deployments of the
cube extension it has not been renamed, neither has cube been made a
reserved keyword. Instead precedence hacking is used to make GROUP BY
cube(..) refer to the CUBE grouping sets feature, and not the function
cube(). To actually group by a function cube(), unlikely as that might
be, the function name has to be quoted.

Needs a catversion bump because stored rules may change.

Author: Andrew Gierth and Atri Sharma, with contributions from Andres Freund
Reviewed-By: Andres Freund, Noah Misch, Tom Lane, Svenne Krap, Tomas
    Vondra, Erik Rijkers, Marti Raudsepp, Pavel Stehule
Discussion: CAOeZVidmVRe2jU6aMk_5qkxnB7dfmPROzM7Ur8JPW5j8Y5X-Lw@mail.gmail.com
2015-05-16 03:46:31 +02:00

654 lines
14 KiB
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/*-------------------------------------------------------------------------
*
* nodes.h
* Definitions for tagged nodes.
*
*
* Portions Copyright (c) 1996-2015, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/include/nodes/nodes.h
*
*-------------------------------------------------------------------------
*/
#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,
/*
* TAGS FOR PLAN NODES (plannodes.h)
*/
T_Plan = 100,
T_Result,
T_ModifyTable,
T_Append,
T_MergeAppend,
T_RecursiveUnion,
T_BitmapAnd,
T_BitmapOr,
T_Scan,
T_SeqScan,
T_IndexScan,
T_IndexOnlyScan,
T_BitmapIndexScan,
T_BitmapHeapScan,
T_TidScan,
T_SubqueryScan,
T_FunctionScan,
T_ValuesScan,
T_CteScan,
T_WorkTableScan,
T_SampleScan,
T_ForeignScan,
T_CustomScan,
T_Join,
T_NestLoop,
T_MergeJoin,
T_HashJoin,
T_Material,
T_Sort,
T_Group,
T_Agg,
T_WindowAgg,
T_Unique,
T_Hash,
T_SetOp,
T_LockRows,
T_Limit,
/* these aren't subclasses of Plan: */
T_NestLoopParam,
T_PlanRowMark,
T_PlanInvalItem,
/*
* TAGS FOR PLAN STATE NODES (execnodes.h)
*
* These should correspond one-to-one with Plan node types.
*/
T_PlanState = 200,
T_ResultState,
T_ModifyTableState,
T_AppendState,
T_MergeAppendState,
T_RecursiveUnionState,
T_BitmapAndState,
T_BitmapOrState,
T_ScanState,
T_SeqScanState,
T_SampleScanState,
T_IndexScanState,
T_IndexOnlyScanState,
T_BitmapIndexScanState,
T_BitmapHeapScanState,
T_TidScanState,
T_SubqueryScanState,
T_FunctionScanState,
T_ValuesScanState,
T_CteScanState,
T_WorkTableScanState,
T_ForeignScanState,
T_CustomScanState,
T_JoinState,
T_NestLoopState,
T_MergeJoinState,
T_HashJoinState,
T_MaterialState,
T_SortState,
T_GroupState,
T_AggState,
T_WindowAggState,
T_UniqueState,
T_HashState,
T_SetOpState,
T_LockRowsState,
T_LimitState,
/*
* TAGS FOR PRIMITIVE NODES (primnodes.h)
*/
T_Alias = 300,
T_RangeVar,
T_Expr,
T_Var,
T_Const,
T_Param,
T_Aggref,
T_GroupingFunc,
T_WindowFunc,
T_ArrayRef,
T_FuncExpr,
T_NamedArgExpr,
T_OpExpr,
T_DistinctExpr,
T_NullIfExpr,
T_ScalarArrayOpExpr,
T_BoolExpr,
T_SubLink,
T_SubPlan,
T_AlternativeSubPlan,
T_FieldSelect,
T_FieldStore,
T_RelabelType,
T_CoerceViaIO,
T_ArrayCoerceExpr,
T_ConvertRowtypeExpr,
T_CollateExpr,
T_CaseExpr,
T_CaseWhen,
T_CaseTestExpr,
T_ArrayExpr,
T_RowExpr,
T_RowCompareExpr,
T_CoalesceExpr,
T_MinMaxExpr,
T_XmlExpr,
T_NullTest,
T_BooleanTest,
T_CoerceToDomain,
T_CoerceToDomainValue,
T_SetToDefault,
T_CurrentOfExpr,
T_InferenceElem,
T_TargetEntry,
T_RangeTblRef,
T_JoinExpr,
T_FromExpr,
T_OnConflictExpr,
T_IntoClause,
/*
* 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_WholeRowVarExprState,
T_AggrefExprState,
T_GroupingFuncExprState,
T_WindowFuncExprState,
T_ArrayRefExprState,
T_FuncExprState,
T_ScalarArrayOpExprState,
T_BoolExprState,
T_SubPlanState,
T_AlternativeSubPlanState,
T_FieldSelectState,
T_FieldStoreState,
T_CoerceViaIOState,
T_ArrayCoerceExprState,
T_ConvertRowtypeExprState,
T_CaseExprState,
T_CaseWhenState,
T_ArrayExprState,
T_RowExprState,
T_RowCompareExprState,
T_CoalesceExprState,
T_MinMaxExprState,
T_XmlExprState,
T_NullTestState,
T_CoerceToDomainState,
T_DomainConstraintState,
/*
* TAGS FOR PLANNER NODES (relation.h)
*/
T_PlannerInfo = 500,
T_PlannerGlobal,
T_RelOptInfo,
T_IndexOptInfo,
T_ParamPathInfo,
T_Path,
T_IndexPath,
T_BitmapHeapPath,
T_BitmapAndPath,
T_BitmapOrPath,
T_NestPath,
T_MergePath,
T_HashPath,
T_TidPath,
T_ForeignPath,
T_CustomPath,
T_AppendPath,
T_MergeAppendPath,
T_ResultPath,
T_MaterialPath,
T_UniquePath,
T_EquivalenceClass,
T_EquivalenceMember,
T_PathKey,
T_RestrictInfo,
T_PlaceHolderVar,
T_SpecialJoinInfo,
T_LateralJoinInfo,
T_AppendRelInfo,
T_PlaceHolderInfo,
T_MinMaxAggInfo,
T_PlannerParamItem,
/*
* TAGS FOR MEMORY NODES (memnodes.h)
*/
T_MemoryContext = 600,
T_AllocSetContext,
/*
* 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 STATEMENT NODES (mostly in 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_AlterDefaultPrivilegesStmt,
T_ClosePortalStmt,
T_ClusterStmt,
T_CopyStmt,
T_CreateStmt,
T_DefineStmt,
T_DropStmt,
T_TruncateStmt,
T_CommentStmt,
T_FetchStmt,
T_IndexStmt,
T_CreateFunctionStmt,
T_AlterFunctionStmt,
T_DoStmt,
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_CreateTableAsStmt,
T_CreateSeqStmt,
T_AlterSeqStmt,
T_VariableSetStmt,
T_VariableShowStmt,
T_DiscardStmt,
T_CreateTrigStmt,
T_CreatePLangStmt,
T_CreateRoleStmt,
T_AlterRoleStmt,
T_DropRoleStmt,
T_LockStmt,
T_ConstraintsSetStmt,
T_ReindexStmt,
T_CheckPointStmt,
T_CreateSchemaStmt,
T_AlterDatabaseStmt,
T_AlterDatabaseSetStmt,
T_AlterRoleSetStmt,
T_CreateConversionStmt,
T_CreateCastStmt,
T_CreateOpClassStmt,
T_CreateOpFamilyStmt,
T_AlterOpFamilyStmt,
T_PrepareStmt,
T_ExecuteStmt,
T_DeallocateStmt,
T_DeclareCursorStmt,
T_CreateTableSpaceStmt,
T_DropTableSpaceStmt,
T_AlterObjectSchemaStmt,
T_AlterOwnerStmt,
T_DropOwnedStmt,
T_ReassignOwnedStmt,
T_CompositeTypeStmt,
T_CreateEnumStmt,
T_CreateRangeStmt,
T_AlterEnumStmt,
T_AlterTSDictionaryStmt,
T_AlterTSConfigurationStmt,
T_CreateFdwStmt,
T_AlterFdwStmt,
T_CreateForeignServerStmt,
T_AlterForeignServerStmt,
T_CreateUserMappingStmt,
T_AlterUserMappingStmt,
T_DropUserMappingStmt,
T_AlterTableSpaceOptionsStmt,
T_AlterTableMoveAllStmt,
T_SecLabelStmt,
T_CreateForeignTableStmt,
T_ImportForeignSchemaStmt,
T_CreateExtensionStmt,
T_AlterExtensionStmt,
T_AlterExtensionContentsStmt,
T_CreateEventTrigStmt,
T_AlterEventTrigStmt,
T_RefreshMatViewStmt,
T_ReplicaIdentityStmt,
T_AlterSystemStmt,
T_CreatePolicyStmt,
T_AlterPolicyStmt,
T_CreateTransformStmt,
/*
* TAGS FOR PARSE TREE NODES (parsenodes.h)
*/
T_A_Expr = 900,
T_ColumnRef,
T_ParamRef,
T_A_Const,
T_FuncCall,
T_A_Star,
T_A_Indices,
T_A_Indirection,
T_A_ArrayExpr,
T_ResTarget,
T_MultiAssignRef,
T_TypeCast,
T_CollateClause,
T_SortBy,
T_WindowDef,
T_RangeSubselect,
T_RangeFunction,
T_TypeName,
T_ColumnDef,
T_IndexElem,
T_Constraint,
T_DefElem,
T_RangeTblEntry,
T_RangeTblFunction,
T_WithCheckOption,
T_SortGroupClause,
T_GroupingSet,
T_WindowClause,
T_PrivGrantee,
T_FuncWithArgs,
T_AccessPriv,
T_CreateOpClassItem,
T_TableLikeClause,
T_FunctionParameter,
T_LockingClause,
T_RowMarkClause,
T_XmlSerialize,
T_WithClause,
T_InferClause,
T_OnConflictClause,
T_CommonTableExpr,
T_RoleSpec,
T_RangeTableSample,
T_TableSampleClause,
/*
* TAGS FOR REPLICATION GRAMMAR PARSE NODES (replnodes.h)
*/
T_IdentifySystemCmd,
T_BaseBackupCmd,
T_CreateReplicationSlotCmd,
T_DropReplicationSlotCmd,
T_StartReplicationCmd,
T_TimeLineHistoryCmd,
/*
* 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 = 950, /* in commands/trigger.h */
T_EventTriggerData, /* in commands/event_trigger.h */
T_ReturnSetInfo, /* in nodes/execnodes.h */
T_WindowObjectData, /* private in nodeWindowAgg.c */
T_TIDBitmap, /* in nodes/tidbitmap.h */
T_InlineCodeBlock, /* in nodes/parsenodes.h */
T_FdwRoutine /* in foreign/fdwapi.h */
} 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) (((const 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(const void *obj);
/*
* nodes/{readfuncs.c,read.c}
*/
extern void *stringToNode(char *str);
/*
* nodes/copyfuncs.c
*/
extern void *copyObject(const void *obj);
/*
* nodes/equalfuncs.c
*/
extern bool equal(const void *a, const 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 or PlannedStmt
*
* This is needed in both parsenodes.h and plannodes.h, so put it here...
*/
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 */
/*
* Semijoins and anti-semijoins (as defined in relational theory) do not
* appear in the SQL JOIN syntax, but there are standard idioms for
* representing them (e.g., using EXISTS). The planner recognizes these
* cases and converts them to joins. So the planner and executor must
* support these codes. NOTE: in JOIN_SEMI output, it is unspecified
* which matching RHS row is joined to. In JOIN_ANTI output, the row is
* guaranteed to be null-extended.
*/
JOIN_SEMI, /* 1 copy of each LHS row that has match(es) */
JOIN_ANTI, /* 1 copy of each LHS row that has no match */
/*
* These codes are used internally in the planner, but are not supported
* by the executor (nor, indeed, by most of the planner).
*/
JOIN_UNIQUE_OUTER, /* LHS path must be made unique */
JOIN_UNIQUE_INNER /* RHS path must be made unique */
/*
* We might need additional join types someday.
*/
} JoinType;
/*
* OUTER joins are those for which pushed-down quals must behave differently
* from the join's own quals. This is in fact everything except INNER and
* SEMI joins. However, this macro must also exclude the JOIN_UNIQUE symbols
* since those are temporary proxies for what will eventually be an INNER
* join.
*
* Note: semijoins are a hybrid case, but we choose to treat them as not
* being outer joins. This is okay principally because the SQL syntax makes
* it impossible to have a pushed-down qual that refers to the inner relation
* of a semijoin; so there is no strong need to distinguish join quals from
* pushed-down quals. This is convenient because for almost all purposes,
* quals attached to a semijoin can be treated the same as innerjoin quals.
*/
#define IS_OUTER_JOIN(jointype) \
(((1 << (jointype)) & \
((1 << JOIN_LEFT) | \
(1 << JOIN_FULL) | \
(1 << JOIN_RIGHT) | \
(1 << JOIN_ANTI))) != 0)
/*
* OnConflictAction -
* "ON CONFLICT" clause type of query
*
* This is needed in both parsenodes.h and plannodes.h, so put it here...
*/
typedef enum OnConflictAction
{
ONCONFLICT_NONE, /* No "ON CONFLICT" clause */
ONCONFLICT_NOTHING, /* ON CONFLICT ... DO NOTHING */
ONCONFLICT_UPDATE /* ON CONFLICT ... DO UPDATE */
} OnConflictAction;
#endif /* NODES_H */
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