Begin implementing DB framework

core/db/storage.py

@@ -0,0 +1,21 @@
+from django.conf import settings
+
+
+def get_db():
+    if settings.DB_BACKEND == "DRUID":
+        from core.db.druid import DruidBackend
+
+        return DruidBackend()
+    elif settings.DB_BACKEND == "OPENSEARCH":
+        from core.db.opensearch import OpensearchBackend
+
+        return OpensearchBackend()
+    elif settings.DB_BACKEND == "MANTICORE":
+        from core.db.manticore import ManticoreBackend
+
+        return ManticoreBackend()
+    else:
+        raise Exception("Invalid DB backend")
+
+
+db = get_db()