executor: AnalyzePartitionConcurrency is not more than number of task (…

…#47463) (#48547)

close #47464

executor/analyze.go

@@ -42,6 +42,7 @@ import (
  "github.com/pingcap/tidb/util/chunk"
  "github.com/pingcap/tidb/util/dbterror/exeerrors"
  "github.com/pingcap/tidb/util/logutil"
+ "github.com/pingcap/tidb/util/mathutil"
  "github.com/pingcap/tidb/util/sqlexec"
  "github.com/pingcap/tipb/go-tipb"
  "go.uber.org/zap"
@@ -184,7 +185,7 @@ func (e *AnalyzeExec) Next(ctx context.Context, _ *chunk.Chunk) error {
  // needGlobalStats used to indicate whether we should merge the partition-level stats to global-level stats.
  needGlobalStats := pruneMode == variable.Dynamic
  globalStatsMap := make(map[globalStatsKey]globalStatsInfo)
- err = e.handleResultsError(ctx, concurrency, needGlobalStats, globalStatsMap, resultsCh)
+ err = e.handleResultsError(ctx, concurrency, needGlobalStats, globalStatsMap, resultsCh, len(tasks))
  for _, task := range tasks {
  if task.colExec != nil && task.colExec.memTracker != nil {
  task.colExec.memTracker.Detach()
@@ -275,10 +276,18 @@ func recordHistoricalStats(sctx sessionctx.Context, tableID int64) error {
 }
 
 // handleResultsError will handle the error fetch from resultsCh and record it in log
-func (e *AnalyzeExec) handleResultsError(ctx context.Context, concurrency int, needGlobalStats bool,
- globalStatsMap globalStatsMap, resultsCh <-chan *statistics.AnalyzeResults) error {
+func (e *AnalyzeExec) handleResultsError(
+ ctx context.Context,
+ concurrency int,
+ needGlobalStats bool,
+ globalStatsMap globalStatsMap,
+ resultsCh <-chan *statistics.AnalyzeResults,
+ taskNum int,
+) error {
  partitionStatsConcurrency := e.ctx.GetSessionVars().AnalyzePartitionConcurrency
- // If 'partitionStatsConcurrency' > 1, we will try to demand extra session from Domain to save Analyze results in concurrency.
+ // the concurrency of handleResultsError cannot be more than partitionStatsConcurrency
+ partitionStatsConcurrency = mathutil.Min(taskNum, partitionStatsConcurrency)
+ // If partitionStatsConcurrency > 1, we will try to demand extra session from Domain to save Analyze results in concurrency.
  // If there is no extra session we can use, we will save analyze results in single-thread.
  if partitionStatsConcurrency > 1 {
  dom := domain.GetDomain(e.ctx)