Fix Latest TS Dao to save newest record with same timestamp. Enabled updates for old timeseries data.

application/src/main/java/org/thingsboard/server/service/subscription/TbEntityDataSubCtx.java

@@ -137,7 +137,8 @@ public class TbEntityDataSubCtx extends TbAbstractDataSubCtx<EntityDataQuery> {
                         for (TsValue update : new ArrayList<>(updateList)) {
                             if (update.getTs() < v.getTs()) {
                                 log.trace("[{}][{}][{}] Removed stale update for key: {} and ts: {}", sessionId, cmdId, subscriptionUpdate.getSubscriptionId(), k, update.getTs());
-                                updateList.remove(update);
+                                // Looks like this is redundant feature and our UI is ready to merge the updates.
+                                //updateList.remove(update);
                             } else if ((update.getTs() == v.getTs() && update.getValue().equals(v.getValue()))) {
                                 log.trace("[{}][{}][{}] Removed duplicate update for key: {} and ts: {}", sessionId, cmdId, subscriptionUpdate.getSubscriptionId(), k, update.getTs());
                                 updateList.remove(update);

dao/src/main/java/org/thingsboard/server/dao/sqlts/SqlTimeseriesLatestDao.java

@@ -123,7 +123,7 @@ public class SqlTimeseriesLatestDao extends BaseAbstractSqlTimeseriesDao impleme
             Map<TsKey, TsKvLatestEntity> trueLatest = new HashMap<>();
             v.forEach(ts -> {
                 TsKey key = new TsKey(ts.getEntityId(), ts.getKey());
-                trueLatest.merge(key, ts, (oldTs, newTs) -> oldTs.getTs() < newTs.getTs() ? newTs : oldTs);
+                trueLatest.merge(key, ts, (oldTs, newTs) -> oldTs.getTs() <= newTs.getTs() ? newTs : oldTs);
             });
             List<TsKvLatestEntity> latestEntities = new ArrayList<>(trueLatest.values());
             if (batchSortEnabled) {