tidb: github.com/pingcap/tidb/statistics/handle Index | Files

package handle

import "github.com/pingcap/tidb/statistics/handle"

Index

Package Files

bootstrap.go ddl.go dump.go gc.go handle.go update.go

Constants

❖
const (
    // DumpAll indicates dump all the delta info in to kv.
    DumpAll dumpMode = true
    // DumpDelta indicates dump part of the delta info in to kv.
    DumpDelta dumpMode = false
)
❖
const (
    // StatsOwnerKey is the stats owner path that is saved to etcd.
    StatsOwnerKey = "/tidb/stats/owner"
    // StatsPrompt is the prompt for stats owner manager.
    StatsPrompt = "stats"
)

Variables

❖
var (
    // MinLogScanCount is the minimum scan count for a feedback to be logged.
    MinLogScanCount = int64(1000)
    // MinLogErrorRate is the minimum error rate for a feedback to be logged.
    MinLogErrorRate = 0.5
)
❖
var AutoAnalyzeMinCnt int64 = 1000

AutoAnalyzeMinCnt means if the count of table is less than this value, we needn't do auto analyze.

❖
var (
    // DumpStatsDeltaRatio is the lower bound of `Modify Count / Table Count` for stats delta to be dumped.
    DumpStatsDeltaRatio = 1 / 10000.0
)
❖
var MaxQueryFeedbackCount = atomic2.NewInt64(1 << 10)

MaxQueryFeedbackCount is the max number of feedback that cache in memory.

func DurationToTS Uses

❖
func DurationToTS(d time.Duration) uint64

DurationToTS converts duration to timestamp.

func NeedAnalyzeTable Uses

❖
func NeedAnalyzeTable(tbl *statistics.Table, limit time.Duration, autoAnalyzeRatio float64, start, end, now time.Time) (bool, string)

NeedAnalyzeTable checks if we need to analyze the table: 1. If the table has never been analyzed, we need to analyze it when it has 

not been modified for a while.

2. If the table had been analyzed before, we need to analyze it when 

"tbl.ModifyCount/tbl.Count > autoAnalyzeRatio" and the current time is
between `start` and `end`.

func TableAnalyzed Uses

❖
func TableAnalyzed(tbl *statistics.Table) bool

TableAnalyzed checks if the table is analyzed.

func TableStatsFromJSON Uses

❖
func TableStatsFromJSON(tableInfo *model.TableInfo, physicalID int64, jsonTbl *JSONTable) (*statistics.Table, error)

TableStatsFromJSON loads statistic from JSONTable and return the Table of statistic.

type Handle Uses

❖
type Handle struct {
    // contains filtered or unexported fields
}

Handle can update stats info periodically.

func NewHandle Uses

❖
func NewHandle(ctx sessionctx.Context, lease time.Duration) *Handle

NewHandle creates a Handle for update stats.

func (*Handle) Clear Uses

❖
func (h *Handle) Clear()

Clear the statsCache, only for test.

func (*Handle) DDLEventCh Uses

❖
func (h *Handle) DDLEventCh() chan *util.Event

DDLEventCh returns ddl events channel in handle.

func (*Handle) DeleteTableStatsFromKV Uses

❖
func (h *Handle) DeleteTableStatsFromKV(physicalID int64) (err error)

DeleteTableStatsFromKV deletes table statistics from kv.

func (*Handle) DumpFeedbackForIndex Uses

❖
func (h *Handle) DumpFeedbackForIndex(q *statistics.QueryFeedback, t *statistics.Table) error

DumpFeedbackForIndex dumps the feedback for index. For queries that contains both equality and range query, we will split them and Update accordingly.

func (*Handle) DumpFeedbackToKV Uses

❖
func (h *Handle) DumpFeedbackToKV(fb *statistics.QueryFeedback) error

DumpFeedbackToKV dumps the given feedback to physical kv layer.

func (*Handle) DumpStatsDeltaToKV Uses

❖
func (h *Handle) DumpStatsDeltaToKV(mode dumpMode) error

DumpStatsDeltaToKV sweeps the whole list and updates the global map, then we dumps every table that held in map to KV. If the mode is `DumpDelta`, it will only dump that delta info that `Modify Count / Table Count` greater than a ratio.

func (*Handle) DumpStatsFeedbackToKV Uses

❖
func (h *Handle) DumpStatsFeedbackToKV() error

DumpStatsFeedbackToKV dumps the stats feedback to KV.

func (*Handle) DumpStatsToJSON Uses

❖
func (h *Handle) DumpStatsToJSON(dbName string, tableInfo *model.TableInfo, historyStatsExec sqlexec.RestrictedSQLExecutor) (*JSONTable, error)

DumpStatsToJSON dumps statistic to json.

func (*Handle) FlushStats Uses

❖
func (h *Handle) FlushStats()

FlushStats flushes the cached stats update into store.

func (*Handle) GCStats Uses

❖
func (h *Handle) GCStats(is infoschema.InfoSchema, ddlLease time.Duration) error

GCStats will garbage collect the useless stats info. For dropped tables, we will first update their version so that other tidb could know that table is deleted.

func (*Handle) GetPartitionStats Uses

❖
func (h *Handle) GetPartitionStats(tblInfo *model.TableInfo, pid int64) *statistics.Table

GetPartitionStats retrieves the partition stats from cache.

func (*Handle) GetQueryFeedback Uses

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func (h *Handle) GetQueryFeedback() []*statistics.QueryFeedback

GetQueryFeedback gets the query feedback. It is only use in test.

func (*Handle) GetTableStats Uses

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func (h *Handle) GetTableStats(tblInfo *model.TableInfo) *statistics.Table

GetTableStats retrieves the statistics table from cache, and the cache will be updated by a goroutine.

func (*Handle) HandleAutoAnalyze Uses

❖
func (h *Handle) HandleAutoAnalyze(is infoschema.InfoSchema)

HandleAutoAnalyze analyzes the newly created table or index.

func (*Handle) HandleDDLEvent Uses

❖
func (h *Handle) HandleDDLEvent(t *util.Event) error

HandleDDLEvent begins to process a ddl task.

func (*Handle) HandleUpdateStats Uses

❖
func (h *Handle) HandleUpdateStats(is infoschema.InfoSchema) error

HandleUpdateStats update the stats using feedback.

func (*Handle) InitStats Uses

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func (h *Handle) InitStats(is infoschema.InfoSchema) (err error)

InitStats will init the stats cache using full load strategy.

func (*Handle) LastUpdateVersion Uses

❖
func (h *Handle) LastUpdateVersion() uint64

LastUpdateVersion gets the last update version.

func (*Handle) Lease Uses

❖
func (h *Handle) Lease() time.Duration

Lease returns the stats lease.

func (*Handle) LoadNeededHistograms Uses

❖
func (h *Handle) LoadNeededHistograms() (err error)

LoadNeededHistograms will load histograms for those needed columns.

func (*Handle) LoadStatsFromJSON Uses

❖
func (h *Handle) LoadStatsFromJSON(is infoschema.InfoSchema, jsonTbl *JSONTable) error

LoadStatsFromJSON will load statistic from JSONTable, and save it to the storage.

func (*Handle) NewSessionStatsCollector Uses

❖
func (h *Handle) NewSessionStatsCollector() *SessionStatsCollector

NewSessionStatsCollector allocates a stats collector for a session.

func (*Handle) RecalculateExpectCount Uses

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func (h *Handle) RecalculateExpectCount(q *statistics.QueryFeedback) error

RecalculateExpectCount recalculates the expect row count if the origin row count is estimated by pseudo.

func (*Handle) SaveMetaToStorage Uses

❖
func (h *Handle) SaveMetaToStorage(tableID, count, modifyCount int64) (err error)

SaveMetaToStorage will save stats_meta to storage.

func (*Handle) SaveStatsToStorage Uses

❖
func (h *Handle) SaveStatsToStorage(tableID int64, count int64, isIndex int, hg *statistics.Histogram, cms *statistics.CMSketch, isAnalyzed int64) (err error)

SaveStatsToStorage saves the stats to storage.

func (*Handle) SetLastUpdateVersion Uses

❖
func (h *Handle) SetLastUpdateVersion(version uint64)

SetLastUpdateVersion sets the last update version.

func (*Handle) SetLease Uses

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func (h *Handle) SetLease(lease time.Duration)

SetLease sets the stats lease.

func (*Handle) Update Uses

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func (h *Handle) Update(is infoschema.InfoSchema) error

Update reads stats meta from store and updates the stats map.

func (*Handle) UpdateErrorRate Uses

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func (h *Handle) UpdateErrorRate(is infoschema.InfoSchema)

UpdateErrorRate updates the error rate of columns from h.rateMap to cache.

func (*Handle) UpdateStatsByLocalFeedback Uses

❖
func (h *Handle) UpdateStatsByLocalFeedback(is infoschema.InfoSchema)

UpdateStatsByLocalFeedback will update statistics by the local feedback. Currently, we dump the feedback with the period of 10 minutes, which means it takes 10 minutes for a feedback to take effect. However, we can use the feedback locally on this tidb-server, so it could be used more timely.

type JSONTable Uses

❖
type JSONTable struct {
    DatabaseName string                 `json:"database_name"`
    TableName    string                 `json:"table_name"`
    Columns      map[string]*jsonColumn `json:"columns"`
    Indices      map[string]*jsonColumn `json:"indices"`
    Count        int64                  `json:"count"`
    ModifyCount  int64                  `json:"modify_count"`
    Partitions   map[string]*JSONTable  `json:"partitions"`
}

JSONTable is used for dumping statistics.

type SessionStatsCollector Uses

❖
type SessionStatsCollector struct {
    sync.Mutex
    // contains filtered or unexported fields
}

SessionStatsCollector is a list item that holds the delta mapper. If you want to write or read mapper, you must lock it.

func (*SessionStatsCollector) Delete Uses

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func (s *SessionStatsCollector) Delete()

Delete only sets the deleted flag true, it will be deleted from list when DumpStatsDeltaToKV is called.

func (*SessionStatsCollector) StoreQueryFeedback Uses

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func (s *SessionStatsCollector) StoreQueryFeedback(feedback interface{}, h *Handle) error

StoreQueryFeedback will merges the feedback into stats collector.

func (*SessionStatsCollector) Update Uses

❖
func (s *SessionStatsCollector) Update(id int64, delta int64, count int64, colSize *map[int64]int64)

Update will updates the delta and count for one table id.

Package handle imports 37 packages (graph) and is imported by 29 packages. Updated 2020-05-30. Refresh now. Tools for package owners.