diff --git a/execution_engine/omop/cohort/recommendation.py b/execution_engine/omop/cohort/recommendation.py
index 695805b6..f132c6d2 100644
--- a/execution_engine/omop/cohort/recommendation.py
+++ b/execution_engine/omop/cohort/recommendation.py
@@ -210,10 +210,10 @@ def reset_state(self) -> None:
 
         Sets all _id attributes to None in the recommendation and all its population/intervention pairs and criteria.
         """
-        self._id = None
+        self.reset_id()
 
         for pi_pair in self.population_intervention_pairs():
-            pi_pair._id = None
+            pi_pair.reset_id()
 
         for criterion in self.atoms():
-            criterion._id = None
+            criterion.reset_id()
diff --git a/execution_engine/omop/db/celida/tables.py b/execution_engine/omop/db/celida/tables.py
index b434d038..444bf5e7 100644
--- a/execution_engine/omop/db/celida/tables.py
+++ b/execution_engine/omop/db/celida/tables.py
@@ -146,7 +146,7 @@ class ResultInterval(Base):  # noqa: D101
     )
 
     result_id: Mapped[int] = mapped_column(
-        Integer, primary_key=True, index=True, autoincrement=True
+        BigInteger, primary_key=True, index=True, autoincrement=True
     )
     run_id = mapped_column(
         ForeignKey(f"{SCHEMA_NAME}.execution_run.run_id"),
@@ -169,9 +169,7 @@ class ResultInterval(Base):  # noqa: D101
     interval_start: Mapped[datetime]
     interval_end: Mapped[datetime]
     interval_type = mapped_column(IntervalTypeEnum)
-    interval_ratio: Mapped[float] = mapped_column(
-        nullable=True
-    )
+    interval_ratio: Mapped[float] = mapped_column(nullable=True)
     execution_run: Mapped["ExecutionRun"] = relationship(
         primaryjoin="ResultInterval.run_id == ExecutionRun.run_id",
     )
diff --git a/execution_engine/task/task.py b/execution_engine/task/task.py
index 78d541c4..85d079bd 100644
--- a/execution_engine/task/task.py
+++ b/execution_engine/task/task.py
@@ -51,6 +51,7 @@ def default_interval_union_with_count(
             interval_type, interval_count = IntervalType.NEGATIVE, 0
         else:
             interval_type, interval_count = interval.type, cast(int, interval.count)
+
         if (
             (
                 interval_type is IntervalType.POSITIVE
@@ -199,14 +200,15 @@ def receives_only_count_inputs(self) -> bool:
         Indicates whether this tasks only receives inputs from expression that perform counting and thus return
         IntervalWithCount.
         """
-        # all arguments are count types
-        if all(isinstance(parent, COUNT_TYPES) for parent in self.expr.args):
-            return True
-
-        # all arguments are logic.BinaryNonCommutativeOperator, and all of their "right" children are count types
+        #  all arguments are either count types or logic.BinaryNonCommutativeOperator
+        #  with their "right" child being a count type, or they have a custom counting function (count_intervals())
         if all(
-            isinstance(parent, logic.BinaryNonCommutativeOperator)
-            and isinstance(parent.right, COUNT_TYPES)
+            (
+                isinstance(parent, logic.BinaryNonCommutativeOperator)
+                and isinstance(parent.right, COUNT_TYPES)
+            )
+            or (isinstance(parent, COUNT_TYPES))
+            or (hasattr(parent, "count_intervals"))
             for parent in self.expr.args
         ):
             return True
diff --git a/execution_engine/util/serializable.py b/execution_engine/util/serializable.py
index 768fe13f..6844aaa6 100644
--- a/execution_engine/util/serializable.py
+++ b/execution_engine/util/serializable.py
@@ -170,7 +170,14 @@ def set_id(self, value: int, overwrite: bool = False) -> None:
         """
         if self._id is not None and not overwrite:
             raise ValueError("Database ID has already been set!")
-        self._id = value
+        object.__setattr__(self, "_id", value)
+
+    def reset_id(self) -> None:
+        """
+        Resets the database ID.
+        """
+        # Circumvents the immutable __setattr__
+        object.__setattr__(self, "_id", None)
 
     @property
     def id(self) -> int: