diff --git a/README.md b/README.md
index 11383e1..53bc9fb 100644
--- a/README.md
+++ b/README.md
@@ -7,8 +7,10 @@
 
 ## Features
 - Collecting album and track metadata into db
+- Tracking album changes
 - Working with `flac` + `cue` music libraries
 
 ## Technologies
-- `SqlAlchemy orm`
-- `Asyncio`
+- `SqlAlchemy orm` for interacting with a db
+- `Asyncio` for using async requests via `asyncpg` driver
+- `PostgreSQL` as db
diff --git a/audiostats/db/api.py b/audiostats/db/api.py
index 8d612ae..87efa2d 100644
--- a/audiostats/db/api.py
+++ b/audiostats/db/api.py
@@ -11,24 +11,36 @@
 logger = logging.getLogger(__name__)
 
 class DBApi:
-    def __init__(self, db_url : str):
+    def __init__(self, db_url : str, workers : int = 5, queue_sz : int = 10):
         self._session_factory = SessionFactory(db_url)
+        self._queue = asyncio.Queue(maxsize=queue_sz)
+        self._num_workers = workers
 
-    async def _upsert_album(self, album : AlbumDTO):
+    async def _album_upserter(self):
         async with self._session_factory as sf:
             unit_of_work = UnitOfWork(sf)
             async with unit_of_work() as uow:
-                await uow.albums.upsert(album)
+                while True:
+                    album = await self._queue.get()
+                    try:
+                        if not album:
+                            break
+                        await uow.albums.upsert(album)
+                    finally:
+                        self._queue.task_done()
 
     async def upsert_albums(self, albums : Iterator[AlbumDTO]):
-        batch = []
+        workers = [asyncio.create_task(self._album_upserter()) for _ in range(self._num_workers)]
+
         for album in albums:
-            batch.append(self._upsert_album(album))
-            if len(batch) > 10:
-                await asyncio.gather(*batch)
-                batch.clear()
-        if batch:
-            await asyncio.gather(*batch)
+            await self._queue.put(album)
+
+        await self._queue.join()
+
+        for _ in range(self._num_workers):
+            await self._queue.put(None)
+
+        await asyncio.gather(*workers)
 
     async def get_all_albums(self):
         async with self._session_factory as sf:
diff --git a/audiostats/db/models.py b/audiostats/db/models.py
index fc4a37f..a798ad6 100644
--- a/audiostats/db/models.py
+++ b/audiostats/db/models.py
@@ -76,7 +76,15 @@ def __str__(self):
 
 
 class AlbumStatus(Base):
-    """Represents **album_statuses** line as orm object"""
+    """Represents **album_statuses** table line as orm object
+
+    :ivar id: AlbumStatus id
+    :ivar album_id: Album id
+    :ivar time_stamp: timestamp when the entry was added
+    :ivar status: insertion status, may be `added` or `modified`
+    :ivar success: processing success, may be `success` or `warning` if there was a warning while process the album cue
+    :ivar album: Relationship to the parent album
+    """
 
     __tablename__ = 'album_statuses'
 
diff --git a/audiostats/handlers/models.py b/audiostats/handlers/models.py
index ae2cc54..ef324b8 100644
--- a/audiostats/handlers/models.py
+++ b/audiostats/handlers/models.py
@@ -1,23 +1,17 @@
+from collections import Counter
 from dataclasses import dataclass, field
-from datetime import datetime
 
 from audiostats.domain import Status, Success
 
-@dataclass(slots=True)
+@dataclass(slots=True, frozen=True)
 class StatusDTO:
     status : Status
     success : Success
-    # timestamp : datetime | None = field(default=None, compare=False)
-
-    # def __eq__(self, other):
-    #     if not isinstance(other, StatusDTO):
-    #         return NotImplemented
-    #     return self.status == other.status and self.success == other.success
 
     def __repr__(self):
         return f'<StatusDTO(status={self.status}, success={self.success})>'
 
-@dataclass(slots=True)
+@dataclass(slots=True, frozen=True)
 class TrackDTO:
     title : str
     number : int | None
@@ -44,4 +38,17 @@ def __repr__(self):
 {'\n'.join(['\t' + repr(i) for i in self.statuses])}
 )>'''
 
+    def __eq__(self, other):
+        if not isinstance(other, AlbumDTO):
+            return False
+        return (
+                self.title == other.title
+                and self.performer == other.performer
+                and self.year == other.year
+                and self.path == other.path
+                and self.cover == other.cover
+                and Counter(self.tracks) == Counter(other.tracks)
+                and Counter(self.statuses) == Counter(other.statuses)
+        )
+