greenplumn CHint 代码
文件路径：/src/backend/gporca/libgpopt/include/gpopt/engine/CHint.h
/---------------------------------------------------------------------------
/ Greenplum Database
/ Copyright (C) 2016 VMware, Inc. or its affiliates.
/
/ @filename:
/ CHint.h
/
/ @doc:
/ Hint configurations
/---------------------------------------------------------------------------
#ifndef GPOPT_CHint_H
#define GPOPT_CHint_H
#include "gpos/base.h"
#include "gpos/common/CRefCount.h"
#include "gpos/memory/CMemoryPool.h"
#define JOIN_ORDER_DP_THRESHOLD ULONG(10)
#define BROADCAST_THRESHOLD ULONG(10000000)
#define PUSH_GROUP_BY_BELOW_SETOP_THRESHOLD ULONG(10)
#define XFORM_BIND_THRESHOLD ULONG(0)
namespace gpopt
{
using namespace gpos;
/---------------------------------------------------------------------------
/ @class:
/ CHint
/
/ @doc:
/ Hint configurations
/
/---------------------------------------------------------------------------
class CHint : public CRefCount
{
private:
ULONG m_ulMinNumOfPartsToRequireSortOnInsert;
ULONG m_ulJoinArityForAssociativityCommutativity;
ULONG m_ulArrayExpansionThreshold;
ULONG m_ulJoinOrderDPLimit;
ULONG m_ulBroadcastThreshold;
BOOL m_fEnforceConstraintsOnDML;
ULONG m_ulPushGroupByBelowSetopThreshold;
ULONG m_ulXform_bind_threshold;
public:
CHint(const CHint &) = delete;
/ ctor
CHint(ULONG min_num_of_parts_to_require_sort_on_insert,
ULONG join_arity_for_associativity_commutativity,
ULONG array_expansion_threshold, ULONG ulJoinOrderDPLimit,
ULONG broadcast_threshold, BOOL enforce_constraint_on_dml,
ULONG push_group_by_below_setop_threshold, ULONG xform_bind_threshold)
: m_ulMinNumOfPartsToRequireSortOnInsert(
min_num_of_parts_to_require_sort_on_insert),
m_ulJoinArityForAssociativityCommutativity(
join_arity_for_associativity_commutativity),
m_ulArrayExpansionThreshold(array_expansion_threshold),
m_ulJoinOrderDPLimit(ulJoinOrderDPLimit),
m_ulBroadcastThreshold(broadcast_threshold),
m_fEnforceConstraintsOnDML(enforce_constraint_on_dml),
m_ulPushGroupByBelowSetopThreshold(
push_group_by_below_setop_threshold),
m_ulXform_bind_threshold(xform_bind_threshold)
{
}
/ Minimum number of partitions required for sorting tuples during
/ insertion in an append only row-oriented partitioned table
ULONG
UlMinNumOfPartsToRequireSortOnInsert() const
{
return m_ulMinNumOfPartsToRequireSortOnInsert;
}
/ Maximum number of relations in an n-ary join operator where ORCA will
/ explore JoinAssociativity and JoinCommutativity transformations.
/ When the number of relations exceed this we'll prune the search space
/ by not pursuing the above mentioned two transformations.
ULONG
UlJoinArityForAssociativityCommutativity() const
{
return m_ulJoinArityForAssociativityCommutativity;
}
/ Maximum number of elements in the scalar comparison with an array which
/ will be expanded for constraint derivation. The benefits of using a smaller number
/ are avoiding expensive expansion of constraints in terms of memory and optimization
/ time. This is used to restrict constructs of following types when the constant-array
/ size is greater than threshold:
/ "(expression) scalar op ANY/ALL (array of constants)" OR
/ "(expression1, expression2) scalar op ANY/ALL ((const-x1, const-y1), ... (const-xn, const-yn))"
ULONG
UlArrayExpansionThreshold() const
{
return m_ulArrayExpansionThreshold;
}
/ Maximum number of relations in an n-ary join operator where ORCA will
/ explore join ordering via dynamic programming.
ULONG
UlJoinOrderDPLimit() const
{
return m_ulJoinOrderDPLimit;
}
/ Maximum number of rows ORCA will broadcast
ULONG
UlBroadcastThreshold() const
{
return m_ulBroadcastThreshold;
}
/ If true, ORCA will add Assertion nodes to the plan to enforce CHECK
/ and NOT NULL constraints on inserted/updated values. (Otherwise it
/ is up to the executor to enforce them.)
BOOL
FEnforceConstraintsOnDML() const
{
return m_fEnforceConstraintsOnDML;
}
/ Skip CXformPushGbBelowSetOp if set op arity is greater than this
ULONG
UlPushGroupByBelowSetopThreshold() const
{
return m_ulPushGroupByBelowSetopThreshold;
}
/ Stop generating alternatives for group expression if bindings exceed this threshold
ULONG
UlXformBindThreshold() const
{
return m_ulXform_bind_threshold;
}
/ generate default hint configurations, which disables sort during insert on
/ append only row-oriented partitioned tables by default
static CHint *
PhintDefault(CMemoryPool *mp)
{
return GPOS_NEW(mp) CHint(
gpos::int_max, /* min_num_of_parts_to_require_sort_on_insert */
gpos::int_max, /* join_arity_for_associativity_commutativity */
gpos::int_max, /* array_expansion_threshold */
JOIN_ORDER_DP_THRESHOLD, /*ulJoinOrderDPLimit*/
BROADCAST_THRESHOLD, /*broadcast_threshold*/
true, /* enforce_constraint_on_dml */
PUSH_GROUP_BY_BELOW_SETOP_THRESHOLD, /* push_group_by_below_setop_threshold */
XFORM_BIND_THRESHOLD /* xform_bind_threshold */
);
}
}; / class CHint
} / namespace gpopt
#endif / !GPOPT_CHint_H
/ EOF