executor: improve channel length for analyze (#47960)

ref #47275
pingcap · Oct 26, 2023 · 6dd6a5e · 6dd6a5e
1 parent a7366f9
commit 6dd6a5e
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Showing 2 changed files with 3 additions and 4 deletions.
diff --git a/pkg/executor/analyze.go b/pkg/executor/analyze.go
@@ -108,8 +108,7 @@ func (e *AnalyzeExec) Next(ctx context.Context, _ *chunk.Chunk) error {
 
 	// Start workers with channel to collect results.
 	taskCh := make(chan *analyzeTask, concurrency)
-	resultChLen := min(concurrency*2, len(tasks))
-	resultsCh := make(chan *statistics.AnalyzeResults, resultChLen)
+	resultsCh := make(chan *statistics.AnalyzeResults, 1)
 	for i := 0; i < concurrency; i++ {
 		e.wg.Run(func() { e.analyzeWorker(taskCh, resultsCh) })
 	}

diff --git a/pkg/executor/analyze_col_v2.go b/pkg/executor/analyze_col_v2.go
@@ -275,8 +275,8 @@ func (e *AnalyzeColumnsExecV2) buildSamplingStats(
 	sc := e.ctx.GetSessionVars().StmtCtx
 
 	// Start workers to merge the result from collectors.
-	mergeResultCh := make(chan *samplingMergeResult, samplingStatsConcurrency)
-	mergeTaskCh := make(chan []byte, samplingStatsConcurrency)
+	mergeResultCh := make(chan *samplingMergeResult, 1)
+	mergeTaskCh := make(chan []byte, 1)
 	var taskEg errgroup.Group
 	// Start read data from resultHandler and send them to mergeTaskCh.
 	taskEg.Go(func() (err error) {