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statistics: batch insert topn and bucket when saving table stats (#35326) #35545

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statistics: batch insert topn and bucket when saving table stats (#35326) #35545

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238 changes: 238 additions & 0 deletions statistics/handle/handle.go
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Original file line number Diff line number Diff line change
Expand Up @@ -18,6 +18,7 @@ import (
"encoding/json"
"fmt"
"strconv"
"strings"
"sync"
"sync/atomic"
"time"
Expand Down Expand Up @@ -953,6 +954,243 @@ func (h *Handle) extendedStatsFromStorage(reader *statsReader, table *statistics
return table, nil
}

<<<<<<< HEAD
=======
// StatsMetaCountAndModifyCount reads count and modify_count for the given table from mysql.stats_meta.
func (h *Handle) StatsMetaCountAndModifyCount(tableID int64) (int64, int64, error) {
reader, err := h.getGlobalStatsReader(0)
if err != nil {
return 0, 0, err
}
defer func() {
err1 := h.releaseGlobalStatsReader(reader)
if err1 != nil && err == nil {
err = err1
}
}()
rows, _, err := reader.read("select count, modify_count from mysql.stats_meta where table_id = %?", tableID)
if err != nil {
return 0, 0, err
}
if len(rows) == 0 {
return 0, 0, nil
}
count := int64(rows[0].GetUint64(0))
modifyCount := rows[0].GetInt64(1)
return count, modifyCount, nil
}

// SaveTableStatsToStorage saves the stats of a table to storage.
func (h *Handle) SaveTableStatsToStorage(results *statistics.AnalyzeResults, needDumpFMS bool) (err error) {
tableID := results.TableID.GetStatisticsID()
statsVer := uint64(0)
defer func() {
if err == nil && statsVer != 0 {
err = h.recordHistoricalStatsMeta(tableID, statsVer)
}
}()
h.mu.Lock()
defer h.mu.Unlock()
ctx := context.TODO()
exec := h.mu.ctx.(sqlexec.SQLExecutor)
_, err = exec.ExecuteInternal(ctx, "begin pessimistic")
if err != nil {
return err
}
defer func() {
err = finishTransaction(context.Background(), exec, err)
}()
txn, err := h.mu.ctx.Txn(true)
if err != nil {
return err
}
version := txn.StartTS()
// 1. Save mysql.stats_meta.
var rs sqlexec.RecordSet
// Lock this row to prevent writing of concurrent analyze.
rs, err = exec.ExecuteInternal(ctx, "select snapshot, count, modify_count from mysql.stats_meta where table_id = %? for update", tableID)
if err != nil {
return err
}
var rows []chunk.Row
rows, err = sqlexec.DrainRecordSet(ctx, rs, h.mu.ctx.GetSessionVars().MaxChunkSize)
if err != nil {
return err
}
var curCnt, curModifyCnt int64
if len(rows) > 0 {
snapshot := rows[0].GetUint64(0)
// A newer version analyze result has been written, so skip this writing.
if snapshot >= results.Snapshot && results.StatsVer == statistics.Version2 {
return nil
}
curCnt = int64(rows[0].GetUint64(1))
curModifyCnt = rows[0].GetInt64(2)
}
if len(rows) == 0 || results.StatsVer != statistics.Version2 {
if _, err = exec.ExecuteInternal(ctx, "replace into mysql.stats_meta (version, table_id, count, snapshot) values (%?, %?, %?, %?)", version, tableID, results.Count, results.Snapshot); err != nil {
return err
}
statsVer = version
} else {
modifyCnt := curModifyCnt - results.BaseModifyCnt
if modifyCnt < 0 {
modifyCnt = 0
}
cnt := curCnt + results.Count - results.BaseCount
if cnt < 0 {
cnt = 0
}
if _, err = exec.ExecuteInternal(ctx, "update mysql.stats_meta set version=%?, modify_count=%?, count=%?, snapshot=%? where table_id=%?", version, modifyCnt, cnt, results.Snapshot, tableID); err != nil {
return err
}
statsVer = version
}
// 2. Save histograms.
const maxInsertLength = 1024 * 1024
for _, result := range results.Ars {
for i, hg := range result.Hist {
// It's normal virtual column, skip it.
if hg == nil {
continue
}
var cms *statistics.CMSketch
if results.StatsVer != statistics.Version2 {
cms = result.Cms[i]
}
cmSketch, err := statistics.EncodeCMSketchWithoutTopN(cms)
if err != nil {
return err
}
fmSketch, err := statistics.EncodeFMSketch(result.Fms[i])
if err != nil {
return err
}
// Delete outdated data
if _, err = exec.ExecuteInternal(ctx, "delete from mysql.stats_top_n where table_id = %? and is_index = %? and hist_id = %?", tableID, result.IsIndex, hg.ID); err != nil {
return err
}
if topN := result.TopNs[i]; topN != nil {
for j := 0; j < len(topN.TopN); {
end := j + batchInsertSize
if end > len(topN.TopN) {
end = len(topN.TopN)
}
sql := new(strings.Builder)
sql.WriteString("insert into mysql.stats_top_n (table_id, is_index, hist_id, value, count) values ")
for k := j; k < end; k++ {
val := sqlexec.MustEscapeSQL("(%?, %?, %?, %?, %?)", tableID, result.IsIndex, hg.ID, topN.TopN[k].Encoded, topN.TopN[k].Count)
if k > j {
val = "," + val
}
if k > j && sql.Len()+len(val) > maxInsertLength {
end = k
break
}
sql.WriteString(val)
}
j = end
if _, err = exec.ExecuteInternal(ctx, sql.String()); err != nil {
return err
}
}
}
if _, err := exec.ExecuteInternal(ctx, "delete from mysql.stats_fm_sketch where table_id = %? and is_index = %? and hist_id = %?", tableID, result.IsIndex, hg.ID); err != nil {
return err
}
if fmSketch != nil && needDumpFMS {
if _, err = exec.ExecuteInternal(ctx, "insert into mysql.stats_fm_sketch (table_id, is_index, hist_id, value) values (%?, %?, %?, %?)", tableID, result.IsIndex, hg.ID, fmSketch); err != nil {
return err
}
}
if _, err = exec.ExecuteInternal(ctx, "replace into mysql.stats_histograms (table_id, is_index, hist_id, distinct_count, version, null_count, cm_sketch, tot_col_size, stats_ver, flag, correlation) values (%?, %?, %?, %?, %?, %?, %?, %?, %?, %?, %?)",
tableID, result.IsIndex, hg.ID, hg.NDV, version, hg.NullCount, cmSketch, hg.TotColSize, results.StatsVer, statistics.AnalyzeFlag, hg.Correlation); err != nil {
return err
}
if _, err = exec.ExecuteInternal(ctx, "delete from mysql.stats_buckets where table_id = %? and is_index = %? and hist_id = %?", tableID, result.IsIndex, hg.ID); err != nil {
return err
}
sc := h.mu.ctx.GetSessionVars().StmtCtx
var lastAnalyzePos []byte
for j := 0; j < len(hg.Buckets); {
end := j + batchInsertSize
if end > len(hg.Buckets) {
end = len(hg.Buckets)
}
sql := new(strings.Builder)
sql.WriteString("insert into mysql.stats_buckets (table_id, is_index, hist_id, bucket_id, count, repeats, lower_bound, upper_bound, ndv) values ")
for k := j; k < end; k++ {
count := hg.Buckets[k].Count
if k > 0 {
count -= hg.Buckets[k-1].Count
}
var upperBound types.Datum
upperBound, err = hg.GetUpper(k).ConvertTo(sc, types.NewFieldType(mysql.TypeBlob))
if err != nil {
return err
}
if k == len(hg.Buckets)-1 {
lastAnalyzePos = upperBound.GetBytes()
}
var lowerBound types.Datum
lowerBound, err = hg.GetLower(k).ConvertTo(sc, types.NewFieldType(mysql.TypeBlob))
if err != nil {
return err
}
val := sqlexec.MustEscapeSQL("(%?, %?, %?, %?, %?, %?, %?, %?, %?)", tableID, result.IsIndex, hg.ID, k, count, hg.Buckets[k].Repeat, lowerBound.GetBytes(), upperBound.GetBytes(), hg.Buckets[k].NDV)
if k > j {
val = "," + val
}
if k > j && sql.Len()+len(val) > maxInsertLength {
end = k
break
}
sql.WriteString(val)
}
j = end
if _, err = exec.ExecuteInternal(ctx, sql.String()); err != nil {
return err
}
}
if len(lastAnalyzePos) > 0 {
if _, err = exec.ExecuteInternal(ctx, "update mysql.stats_histograms set last_analyze_pos = %? where table_id = %? and is_index = %? and hist_id = %?", lastAnalyzePos, tableID, result.IsIndex, hg.ID); err != nil {
return err
}
}
if result.IsIndex == 0 {
if _, err = exec.ExecuteInternal(ctx, "insert into mysql.column_stats_usage (table_id, column_id, last_analyzed_at) values(%?, %?, current_timestamp()) on duplicate key update last_analyzed_at = values(last_analyzed_at)", tableID, hg.ID); err != nil {
return err
}
}
}
}
// 3. Save extended statistics.
extStats := results.ExtStats
if extStats == nil || len(extStats.Stats) == 0 {
return nil
}
var bytes []byte
var statsStr string
for name, item := range extStats.Stats {
bytes, err = json.Marshal(item.ColIDs)
if err != nil {
return err
}
strColIDs := string(bytes)
switch item.Tp {
case ast.StatsTypeCardinality, ast.StatsTypeCorrelation:
statsStr = fmt.Sprintf("%f", item.ScalarVals)
case ast.StatsTypeDependency:
statsStr = item.StringVals
}
if _, err = exec.ExecuteInternal(ctx, "replace into mysql.stats_extended values (%?, %?, %?, %?, %?, %?, %?)", name, item.Tp, tableID, strColIDs, statsStr, version, StatsStatusAnalyzed); err != nil {
return err
}
}
return
}

>>>>>>> 6266817ce... statistics: batch insert topn and bucket when saving table stats (#35326)
// SaveStatsToStorage saves the stats to storage.
func (h *Handle) SaveStatsToStorage(tableID int64, count int64, isIndex int, hg *statistics.Histogram, cms *statistics.CMSketch, topN *statistics.TopN, fms *statistics.FMSketch, statsVersion int, isAnalyzed int64) (err error) {
h.mu.Lock()
Expand Down