This class produces an estimate of the size of each field in a table. More...

Classes
struct	Estimate
	A size estimate for a field. More...

Public Types
using	EstimateArray = Prealloced_array< Estimate, 32 >
	Size estimates for all fields. More...

Public Member Functions
	FieldSizeEstimator (const TABLE *table)

const EstimateArray &	estimates () const

Private Attributes
EstimateArray	m_estimates {PSI_NOT_INSTRUMENTED}
	Size estimates for all fields. More...

Detailed Description

This class produces an estimate of the size of each field in a table.

For fixed-size fields, the estimates should be accurate. But since there is no statistics on the length of variable size fields, we use heuristics to estimate these.

Member Typedef Documentation

◆ EstimateArray

using FieldSizeEstimator::EstimateArray = Prealloced_array<Estimate, 32>

Size estimates for all fields.

Constructor & Destructor Documentation

◆ FieldSizeEstimator()

FieldSizeEstimator::FieldSizeEstimator ( const TABLE * table )

explicit

Member Function Documentation

◆ estimates()

const EstimateArray & FieldSizeEstimator::estimates ( ) const

inline

Member Data Documentation

◆ m_estimates

EstimateArray FieldSizeEstimator::m_estimates {PSI_NOT_INSTRUMENTED}

private

Size estimates for all fields.

The documentation for this class was generated from the following file:

sql/join_optimizer/cost_model.cc

Classes

Public Types

Public Member Functions

Private Attributes