diff --git a/executor/index_merge_reader.go b/executor/index_merge_reader.go
index 7ab9cd1faa76d..e11058c6c7f3c 100644
--- a/executor/index_merge_reader.go
+++ b/executor/index_merge_reader.go
@@ -253,7 +253,7 @@ func (e *IndexMergeReaderExecutor) startIndexMergeProcessWorker(ctx context.Cont
 	}()
 }
 
-func (e *IndexMergeReaderExecutor) startPartialIndexWorker(ctx context.Context, exitCh <-chan struct{}, fetchCh chan<- *lookupTableTask, workID int) (err error) {
+func (e *IndexMergeReaderExecutor) startPartialIndexWorker(ctx context.Context, exitCh <-chan struct{}, fetchCh chan<- *lookupTableTask, workID int) error {
 	if e.runtimeStats != nil {
 		collExec := true
 		e.dagPBs[workID].CollectExecutionSummaries = &collExec
@@ -288,6 +288,7 @@ func (e *IndexMergeReaderExecutor) startPartialIndexWorker(ctx context.Context,
 
 				if e.isCorColInPartialFilters[workID] {
 					// We got correlated column, so need to refresh Selection operator.
+					var err error
 					if e.dagPBs[workID].Executors, _, err = constructDistExec(e.ctx, e.partialPlans[workID]); err != nil {
 						worker.syncErr(e.resultCh, err)
 						return
@@ -359,7 +360,7 @@ func (e *IndexMergeReaderExecutor) startPartialIndexWorker(ctx context.Context,
 	return nil
 }
 
-func (e *IndexMergeReaderExecutor) startPartialTableWorker(ctx context.Context, exitCh <-chan struct{}, fetchCh chan<- *lookupTableTask, workID int) (err error) {
+func (e *IndexMergeReaderExecutor) startPartialTableWorker(ctx context.Context, exitCh <-chan struct{}, fetchCh chan<- *lookupTableTask, workID int) error {
 	ts := e.partialPlans[workID][0].(*plannercore.PhysicalTableScan)
 
 	tbls := make([]table.Table, 0, 1)
@@ -376,6 +377,7 @@ func (e *IndexMergeReaderExecutor) startPartialTableWorker(ctx context.Context,
 		defer e.idxWorkerWg.Done()
 		util.WithRecovery(
 			func() {
+				var err error
 				partialTableReader := &TableReaderExecutor{
 					baseExecutor:     newBaseExecutor(e.ctx, ts.Schema(), e.getPartitalPlanID(workID)),
 					dagPB:            e.dagPBs[workID],
@@ -415,8 +417,7 @@ func (e *IndexMergeReaderExecutor) startPartialTableWorker(ctx context.Context,
 
 					// init partialTableReader and partialTableWorker again for the next table
 					partialTableReader.table = tbl
-					err := partialTableReader.Open(ctx)
-					if err != nil {
+					if err = partialTableReader.Open(ctx); err != nil {
 						logutil.Logger(ctx).Error("open Select result failed:", zap.Error(err))
 						worker.syncErr(e.resultCh, err)
 						break
@@ -438,7 +439,7 @@ func (e *IndexMergeReaderExecutor) startPartialTableWorker(ctx context.Context,
 
 					// release related resources
 					cancel()
-					if err := worker.tableReader.Close(); err != nil {
+					if err = worker.tableReader.Close(); err != nil {
 						logutil.Logger(ctx).Error("close Select result failed:", zap.Error(err))
 					}
 					e.ctx.StoreQueryFeedback(e.feedbacks[workID])