import "github.com/pingcap/tidb/statistics/handle"
bootstrap.go ddl.go dump.go gc.go handle.go update.go
const (
// StatsStatusInited is the status for extended stats which are just registered but have not been analyzed yet.
StatsStatusInited uint8 = iota
// StatsStatusAnalyzed is the status for extended stats which have been collected in analyze.
StatsStatusAnalyzed
// StatsStatusDeleted is the status for extended stats which were dropped. These "deleted" records would be removed from storage by GCStats().
StatsStatusDeleted
)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"
)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
)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
)DurationToTS converts duration to timestamp.
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(tbl *statistics.Table) bool
TableAnalyzed checks if the table is analyzed.
func TableStatsFromJSON(tableInfo *model.TableInfo, physicalID int64, jsonTbl *JSONTable) (*statistics.Table, error)
TableStatsFromJSON loads statistic from JSONTable and return the Table of statistic.
GlobalIndexID is the key type for indexUsageMap.
type Handle struct {
// contains filtered or unexported fields
}Handle can update stats info periodically.
NewHandle creates a Handle for update stats.
func (h *Handle) BuildExtendedStats(tableID int64, cols []*model.ColumnInfo, collectors []*statistics.SampleCollector) (*statistics.ExtendedStatsColl, error)
BuildExtendedStats build extended stats for column groups if needed based on the column samples.
Clear the statsCache, only for test.
func (h *Handle) CurrentPruneMode() variable.PartitionPruneMode
CurrentPruneMode indicates whether tbl support runtime prune for table and first partition id.
DDLEventCh returns ddl events channel in handle.
DeleteTableStatsFromKV deletes table statistics from kv.
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 (h *Handle) DumpFeedbackToKV(fb *statistics.QueryFeedback) error
DumpFeedbackToKV dumps the given feedback to physical kv layer.
DumpIndexUsageToKV will dump in-memory index usage information to KV.
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.
DumpStatsFeedbackToKV dumps the stats feedback to KV.
func (h *Handle) DumpStatsToJSON(dbName string, tableInfo *model.TableInfo, historyStatsExec sqlexec.RestrictedSQLExecutor) (*JSONTable, error)
DumpStatsToJSON dumps statistic to json.
FlushStats flushes the cached stats update into store.
GCIndexUsage will delete the usage information of those indexes that do not exist.
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.
GetMemConsumed returns the mem size of statscache consumed
GetPartitionStats retrieves the partition stats from cache.
func (h *Handle) GetQueryFeedback() *statistics.QueryFeedbackMap
GetQueryFeedback gets the query feedback. It is only used in test.
GetTableStats retrieves the statistics table from cache, and the cache will be updated by a goroutine.
func (h *Handle) HandleAutoAnalyze(is infoschema.InfoSchema)
HandleAutoAnalyze analyzes the newly created table or index.
HandleDDLEvent begins to process a ddl task.
func (h *Handle) HandleUpdateStats(is infoschema.InfoSchema) error
HandleUpdateStats update the stats using feedback.
func (h *Handle) InitStats(is infoschema.InfoSchema) (err error)
InitStats will init the stats cache using full load strategy.
func (h *Handle) InsertExtendedStats(statsName string, colIDs []int64, tp int, tableID int64, ifNotExists bool) (err error)
InsertExtendedStats inserts a record into mysql.stats_extended and update version in mysql.stats_meta.
LastUpdateVersion gets the last update version.
Lease returns the stats lease.
LoadNeededHistograms will load histograms for those needed columns.
func (h *Handle) LoadStatsFromJSON(is infoschema.InfoSchema, jsonTbl *JSONTable) error
LoadStatsFromJSON will load statistic from JSONTable, and save it to the storage.
func (h *Handle) MarkExtendedStatsDeleted(statsName string, tableID int64, ifExists bool) (err error)
MarkExtendedStatsDeleted update the status of mysql.stats_extended to be `deleted` and the version of mysql.stats_meta.
func (h *Handle) NewSessionIndexUsageCollector() *SessionIndexUsageCollector
NewSessionIndexUsageCollector will add a new SessionIndexUsageCollector into linked list headed by idxUsageListHead. idxUsageListHead always points to an empty SessionIndexUsageCollector as a sentinel node. So we let idxUsageListHead.next points to new item. It's helpful to sweepIdxUsageList.
func (h *Handle) NewSessionStatsCollector() *SessionStatsCollector
NewSessionStatsCollector allocates a stats collector for a session.
func (h *Handle) RecalculateExpectCount(q *statistics.QueryFeedback) error
RecalculateExpectCount recalculates the expect row count if the origin row count is estimated by pseudo.
RefreshVars uses to pull PartitionPruneMethod vars from kv storage.
ReloadExtendedStatistics drops the cache for extended statistics and reload data from mysql.stats_extended.
func (h *Handle) SaveExtendedStatsToStorage(tableID int64, extStats *statistics.ExtendedStatsColl, isLoad bool) (err error)
SaveExtendedStatsToStorage writes extended stats of a table into mysql.stats_extended.
SaveMetaToStorage will save stats_meta to storage.
func (h *Handle) SaveStatsToStorage(tableID int64, count int64, isIndex int, hg *statistics.Histogram, cms *statistics.CMSketch, topN *statistics.TopN, statsVersion int, isAnalyzed int64) (err error)
SaveStatsToStorage saves the stats to storage.
SetLastUpdateVersion sets the last update version.
SetLease sets the stats lease.
func (h *Handle) Update(is infoschema.InfoSchema) error
Update reads stats meta from store and updates the stats map.
func (h *Handle) UpdateErrorRate(is infoschema.InfoSchema)
UpdateErrorRate updates the error rate of columns from h.rateMap to cache.
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.
IndexUsageInformation is the data struct to store index usage information.
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"`
ExtStats []*jsonExtendedStats `json:"ext_stats"`
Count int64 `json:"count"`
ModifyCount int64 `json:"modify_count"`
Partitions map[string]*JSONTable `json:"partitions"`
}JSONTable is used for dumping statistics.
SessionIndexUsageCollector is a list item that holds the index usage mapper. If you want to write or read mapper, you must lock it.
func (s *SessionIndexUsageCollector) Delete()
Delete will set s.deleted to true which means it can be deleted from linked list.
func (s *SessionIndexUsageCollector) Update(tableID int64, indexID int64, value *IndexUsageInformation)
Update updates the mapper in SessionIndexUsageCollector.
SessionStatsCollector is a list item that holds the delta mapper. If you want to write or read mapper, you must lock it.
func (s *SessionStatsCollector) Delete()
Delete only sets the deleted flag true, it will be deleted from list when DumpStatsDeltaToKV is called.
func (s *SessionStatsCollector) StoreQueryFeedback(feedback interface{}, h *Handle) error
StoreQueryFeedback merges the feedback into stats collector.
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 39 packages (graph) and is imported by 29 packages. Updated 2021-01-25. Refresh now. Tools for package owners.