planner: remove useless todo comment and fix some typos for index merge (#46934)

executor/index_merge_reader.go

@@ -593,7 +593,7 @@ type partialTableWorker struct {
 	pushedLimit        *plannercore.PushedDownLimit
 }
 
-// needPartitionHandle indicates whether we need create a partitonHandle or not.
+// needPartitionHandle indicates whether we need create a partitionHandle or not.
 // If the schema from planner part contains ExtraPhysTblID,
 // we need create a partitionHandle, otherwise create a normal handle.
 // In TableRowIDScan, the partitionHandle will be used to create key ranges.
@@ -1504,7 +1504,7 @@ func syncErr(ctx context.Context, finished <-chan struct{}, errCh chan<- *indexM
 	}
 }
 
-// needPartitionHandle indicates whether we need create a partitonHandle or not.
+// needPartitionHandle indicates whether we need create a partitionHandle or not.
 // If the schema from planner part contains ExtraPidColID or ExtraPhysTblID,
 // we need create a partitionHandle, otherwise create a normal handle.
 // In TableRowIDScan, the partitionHandle will be used to create key ranges.
@@ -1692,7 +1692,7 @@ func (w *indexMergeTableScanWorker) pickAndExecTask(ctx context.Context, task **
 			}
 		}
 		// Make sure panic failpoint is after fetch task from workCh.
-		// Otherwise cannot send error to task.doneCh.
+		// Otherwise, cannot send error to task.doneCh.
 		failpoint.Inject("testIndexMergePanicTableScanWorker", nil)
 		execStart := time.Now()
 		err := w.executeTask(ctx, *task)

executor/test/indexmergereadtest/index_merge_reader_test.go

@@ -611,8 +611,6 @@ func TestPessimisticLockOnPartitionForIndexMerge(t *testing.T) {
 	require.Equal(t, <-ch, int32(1))
 	require.Equal(t, <-ch, int32(0))
 	<-ch // wait for goroutine to quit.
-
-	// TODO: add support for index merge reader in dynamic tidb_partition_prune_mode
 }
 
 func TestIndexMergeIntersectionConcurrency(t *testing.T) {
@@ -736,7 +734,7 @@ func TestIntersectionWithDifferentConcurrency(t *testing.T) {
 					tk.MustQuery(fmt.Sprintf("select /*+ use_index_merge(t1, primary, c2, c3) */ c1 from t1 where c2 < 1024 and c3 > %d", c3)).Sort().Check(res)
 				}
 
-				// In tranaction
+				// In transaction
 				for i := 0; i < queryCnt; i++ {
 					tk.MustExec("begin;")
 					r := rand.Intn(3)