Simplify the format index name logical in ES storage (#9145)

docs/en/changes/changes.md

@@ -74,6 +74,7 @@
 * Add `profileDataQueryBatchSize` config in Elasticsearch Storage.
 * Add APIs to query Pod log on demand.
 * Remove OAL for events.
+* Simplify the format index name logical in ES storage.
 
 #### UI
 

oap-server/server-storage-plugin/storage-elasticsearch-plugin/src/main/java/org/apache/skywalking/oap/server/storage/plugin/elasticsearch/base/TimeSeriesUtils.java

@@ -49,18 +49,12 @@ public class TimeSeriesUtils {
      * @return formatted latest index name, based on current timestamp.
      */
     public static String latestWriteIndexName(Model model) {
-        long timeBucket;
         String tableName = IndexController.INSTANCE.getTableName(model);
+        long dayTimeBucket = TimeBucket.getTimeBucket(System.currentTimeMillis(), DownSampling.Day);
         if (model.isRecord() && model.isSuperDataset()) {
-            timeBucket = TimeBucket.getTimeBucket(System.currentTimeMillis(), model.getDownsampling());
-            return tableName + Const.LINE + compressTimeBucket(timeBucket / 1000000, SUPER_DATASET_DAY_STEP);
-        } else if (model.isRecord()) {
-            timeBucket = TimeBucket.getTimeBucket(System.currentTimeMillis(), model.getDownsampling());
-            return tableName + Const.LINE + compressTimeBucket(timeBucket / 1000000, DAY_STEP);
-        } else {
-            timeBucket = TimeBucket.getTimeBucket(System.currentTimeMillis(), DownSampling.Minute);
-            return tableName + Const.LINE + compressTimeBucket(timeBucket / 10000, DAY_STEP);
+            return tableName + Const.LINE + compressTimeBucket(dayTimeBucket, SUPER_DATASET_DAY_STEP);
         }
+        return tableName + Const.LINE + compressTimeBucket(dayTimeBucket, DAY_STEP);
     }
 
     /**