stats

package
v0.18.0 Latest Latest
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 Go to latest Published: Feb 28, 2024 License: Apache-2.0 Imports: 14 Imported by: 5

Documentation

Overview

Copyright 2023 Dolthub, Inc.

Licensed 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.

Index

Constants

This section is empty.

Variables

View Source 
var ErrJoinStringStatistics = errors.New("joining string histograms is unsupported")

Functions

func AlignBuckets 

func AlignBuckets(h1, h2 sql.Histogram, lBound1, lBound2 sql.Row, s1Types, s2Types []sql.Type, cmp func(sql.Row, sql.Row) (int, error)) (sql.Histogram, sql.Histogram, error)

AlignBuckets produces two histograms with the same number of buckets. Start by using upper bound keys to truncate histogram with a larger keyspace. Then for every misaligned pair of buckets, cut the one with the higher bound value on the smaller's key. We use a linear interpolation to divide keys when splitting.

func Empty 

func Empty(s sql.Statistic) bool

func IndexFds 

func IndexFds(tableName string, sch sql.Schema, idx sql.Index) (*sql.FuncDepSet, sql.ColSet, error)

func InterpolateNewCounts 

func InterpolateNewCounts(from, to sql.Statistic) sql.Statistic

func Intersect 

func Intersect(s1, s2 sql.Statistic) sql.Statistic

func Join 

func Join(s1, s2 sql.Statistic, prefixCnt int, debug bool) (sql.Statistic, error)

Join performs an alignment algorithm on two sets of statistics, and then pairwise estimates bucket cardinalities by joining most common values (mcvs) directly and assuming key uniformity otherwise. Only numeric types are supported.

func McvPrefixGt 

func McvPrefixGt(statistic sql.Statistic, i int, val interface{}) (sql.Statistic, error)

func McvPrefixGte 

func McvPrefixGte(statistic sql.Statistic, i int, val interface{}) (sql.Statistic, error)

func McvPrefixIsNotNull 

func McvPrefixIsNotNull(statistic sql.Statistic, i int, val interface{}) (sql.Statistic, error)

func McvPrefixIsNull 

func McvPrefixIsNull(statistic sql.Statistic, i int, val interface{}) (sql.Statistic, error)

func McvPrefixLt 

func McvPrefixLt(statistic sql.Statistic, i int, val interface{}) (sql.Statistic, error)

func McvPrefixLte 

func McvPrefixLte(statistic sql.Statistic, i int, val interface{}) (sql.Statistic, error)

func NewExpDistIter 

func NewExpDistIter(colCnt, rowCnt int, lambda float64) sql.RowIter

func NewNormDistIter 

func NewNormDistIter(colCnt, rowCnt int, mean, std float64) sql.RowIter

func ParseTypeStrings 

func ParseTypeStrings(typs []string) ([]sql.Type, error)

func PrefixGt 

func PrefixGt(statistic sql.Statistic, val interface{}) (sql.Statistic, error)

func PrefixGtHist 

func PrefixGtHist(h sql.Histogram, target sql.Row, cmp func(sql.Row, sql.Row) (int, error)) (int, error)

func PrefixGte 

func PrefixGte(statistic sql.Statistic, val interface{}) (sql.Statistic, error)

func PrefixGteHist 

func PrefixGteHist(h sql.Histogram, target sql.Row, cmp func(sql.Row, sql.Row) (int, error)) (int, error)

func PrefixIsNotNull 

func PrefixIsNotNull(statistic sql.Statistic) (sql.Statistic, error)

func PrefixIsNull 

func PrefixIsNull(statistic sql.Statistic) (sql.Statistic, error)

func PrefixKey 

func PrefixKey(statistic sql.Statistic, key []interface{}, nullable []bool) (sql.Statistic, error)

func PrefixLt 

func PrefixLt(statistic sql.Statistic, val interface{}) (sql.Statistic, error)

func PrefixLtHist 

func PrefixLtHist(h sql.Histogram, target sql.Row, cmp func(sql.Row, sql.Row) (int, error)) (int, error)

func PrefixLte 

func PrefixLte(statistic sql.Statistic, val interface{}) (sql.Statistic, error)

func PrefixLteHist 

func PrefixLteHist(h sql.Histogram, target sql.Row, cmp func(sql.Row, sql.Row) (int, error)) (int, error)

func Union 

func Union(s1, s2 sql.Statistic) sql.Statistic

func UpdateCounts 

func UpdateCounts(statistic sql.Statistic) sql.Statistic

Types

type Bucket 

type Bucket struct {
	RowCnt      uint64    `json:"row_count"`
	DistinctCnt uint64    `json:"distinct_count"`
	NullCnt     uint64    `json:"null_count"`
	McvsCnt     []uint64  `json:"mcv_counts"`
	BoundCnt    uint64    `json:"bound_count"`
	BoundVal    sql.Row   `json:"upper_bound"`
	McvVals     []sql.Row `json:"mcvs"`
}

func NewHistogramBucket 

func NewHistogramBucket(rowCount, distinctCount, nullCount, boundCount uint64, boundValue sql.Row, mcvCounts []uint64, mcvs []sql.Row) *Bucket

func (Bucket) BoundCount 

func (b Bucket) BoundCount() uint64

func (Bucket) DistinctCount 

func (b Bucket) DistinctCount() uint64

func (Bucket) McvCounts 

func (b Bucket) McvCounts() []uint64

func (Bucket) Mcvs 

func (b Bucket) Mcvs() []sql.Row

func (Bucket) NullCount 

func (b Bucket) NullCount() uint64

func (Bucket) RowCount 

func (b Bucket) RowCount() uint64

func (Bucket) UpperBound 

func (b Bucket) UpperBound() sql.Row

type HeapRow 

type HeapRow struct {
	Row   sql.Row
	Count int
}

func NewHeapRow 

func NewHeapRow(r sql.Row, cnt int) HeapRow

type SqlHeap 

type SqlHeap struct {
	// contains filtered or unexported fields
}

An SqlHeap is a min-heap of ints.

func NewSqlHeap 

func NewSqlHeap(k int) *SqlHeap

func (SqlHeap) Array 

func (h SqlHeap) Array() []sql.Row

func (SqlHeap) Counts 

func (h SqlHeap) Counts() []uint64

func (SqlHeap) Len 

func (h SqlHeap) Len() int

func (SqlHeap) Less 

func (h SqlHeap) Less(i, j int) bool

func (*SqlHeap) Pop 

func (h *SqlHeap) Pop() any

func (*SqlHeap) Push 

func (h *SqlHeap) Push(x any)

func (SqlHeap) Swap 

func (h SqlHeap) Swap(i, j int)

type Statistic 

type Statistic struct {
	RowCnt      uint64            `json:"row_count"`
	DistinctCnt uint64            `json:"distinct_count"`
	NullCnt     uint64            `json:"null_count"`
	AvgRowSize  uint64            `json:"avg_size"`
	Created     time.Time         `json:"created_at"`
	Qual        sql.StatQualifier `json:"qualifier"`
	Cols        []string          `json:"columns"`
	Typs        []sql.Type        `json:"-"`
	Hist        []*Bucket         `json:"buckets"`
	IdxClass    uint8             `json:"index_class"`
	LowerBnd    sql.Row           `json:"lower_bound"`
	// contains filtered or unexported fields
}

func NewStatistic 

func NewStatistic(rowCount, distinctCount, nullCount, avgSize uint64, createdAt time.Time, qualifier sql.StatQualifier, columns []string, types []sql.Type, histogram []*Bucket, class sql.IndexClass, lowerBound sql.Row) *Statistic

func (*Statistic) AvgSize 

func (s *Statistic) AvgSize() uint64

func (*Statistic) ColSet 

func (s *Statistic) ColSet() sql.ColSet

func (*Statistic) Columns 

func (s *Statistic) Columns() []string

func (*Statistic) CreatedAt 

func (s *Statistic) CreatedAt() time.Time

func (*Statistic) DistinctCount 

func (s *Statistic) DistinctCount() uint64

func (*Statistic) FuncDeps 

func (s *Statistic) FuncDeps() *sql.FuncDepSet

func (*Statistic) Histogram 

func (s *Statistic) Histogram() sql.Histogram

func (*Statistic) IndexClass 

func (s *Statistic) IndexClass() sql.IndexClass

func (*Statistic) LowerBound 

func (s *Statistic) LowerBound() sql.Row

func (*Statistic) NullCount 

func (s *Statistic) NullCount() uint64

func (*Statistic) Qualifier 

func (s *Statistic) Qualifier() sql.StatQualifier

func (*Statistic) RowCount 

func (s *Statistic) RowCount() uint64

func (*Statistic) SetColumns 

func (s *Statistic) SetColumns(c []string)

func (*Statistic) SetQualifier 

func (s *Statistic) SetQualifier(q sql.StatQualifier)

func (*Statistic) SetTypes 

func (s *Statistic) SetTypes(t []sql.Type)

func (*Statistic) ToInterface 

func (s *Statistic) ToInterface() interface{}

func (*Statistic) Types 

func (s *Statistic) Types() []sql.Type

func (*Statistic) WithAvgSize 

func (s *Statistic) WithAvgSize(i uint64) sql.Statistic

func (*Statistic) WithColSet 

func (s *Statistic) WithColSet(cols sql.ColSet) sql.Statistic

func (*Statistic) WithDistinctCount 

func (s *Statistic) WithDistinctCount(i uint64) sql.Statistic

func (*Statistic) WithFuncDeps 

func (s *Statistic) WithFuncDeps(fds *sql.FuncDepSet) sql.Statistic

func (*Statistic) WithHistogram 

func (s *Statistic) WithHistogram(h sql.Histogram) (sql.Statistic, error)

func (*Statistic) WithLowerBound 

func (s *Statistic) WithLowerBound(r sql.Row) sql.Statistic

func (*Statistic) WithNullCount 

func (s *Statistic) WithNullCount(i uint64) sql.Statistic

func (*Statistic) WithRowCount 

func (s *Statistic) WithRowCount(i uint64) sql.Statistic

Source Files

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