better code

pkg/statistics/handle/storage/stats_read_writer.go

@@ -740,23 +740,31 @@ func (s *statsReadWriter) SaveColumnStatsUsageToStorage(physicalID int64, predic
 				continue
 			}
 			itemID := model.TableItemID{TableID: physicalID, ID: col.ID}
-			info := statstypes.ColStatsTimeInfo{}
-			if col.LastUsedAt != nil {
-				lastUsedAtTime, err := types.ParseTime(types.DefaultStmtNoWarningContext, *col.LastUsedAt, mysql.TypeTimestamp, types.MaxFsp)
-				if err != nil {
-					return err
-				}
-				info.LastUsedAt = &lastUsedAtTime
+			lastUsedAt, err := parseTimeOrNil(col.LastUsedAt)
+			if err != nil {
+				return err
 			}
-			if col.LastAnalyzedAt != nil {
-				lastAnalyzedAtTime, err := types.ParseTime(types.DefaultStmtNoWarningContext, *col.LastAnalyzedAt, mysql.TypeTimestamp, types.MaxFsp)
-				if err != nil {
-					return err
-				}
-				info.LastAnalyzedAt = &lastAnalyzedAtTime
+			lastAnalyzedAt, err := parseTimeOrNil(col.LastAnalyzedAt)
+			if err != nil {
+				return err
+			}
+			colStatsUsage[itemID] = statstypes.ColStatsTimeInfo{
+				LastUsedAt:     lastUsedAt,
+				LastAnalyzedAt: lastAnalyzedAt,
 			}
-			colStatsUsage[itemID] = info
 		}
 		return predicatecolumn.SaveColumnStatsUsageForTable(sctx, colStatsUsage)
 	}, util.FlagWrapTxn)
 }
+
+func parseTimeOrNil(timeStr *string) (*types.Time, error) {
+	if timeStr == nil {
+		return nil, nil
+	}
+	// DefaultStmtNoWarningContext use UTC timezone.
+	parsedTime, err := types.ParseTime(types.DefaultStmtNoWarningContext, *timeStr, mysql.TypeTimestamp, types.MaxFsp)
+	if err != nil {
+		return nil, err
+	}
+	return &parsedTime, nil
+}