CR

distribution/lib/Standard/Database/0.0.0-dev/src/Internal/Hidden_Table_Registry.enso

@@ -26,18 +26,27 @@ type Hidden_Table_Registry
     Registry (reference_counter : HiddenTableReferenceCounter)
 
     ## PRIVATE
+       Creates a new reference to the table with the given name.
+
+       Once this and any other references to this table name are garbage
+       collected, the table will be scheduled for disposal and removed on the
+       next `run_maintenance_table_cleanup` invocation (unless the table is
+       'brought back to life' by new references being introduced).
     make_reference : Text -> Managed_Resource
     make_reference self table_name =
         self.reference_counter.increment table_name
         reference = Hidden_Table_Reference.Reference self table_name
         Managed_Resource.register reference dispose_reference
 
     ## PRIVATE
+       Lists all tables that were added to the registry by calling
+       `make_reference` and not yet removed.
     list_hidden_tables : Vector Text
     list_hidden_tables self =
         Vector.from_polyglot_array self.reference_counter.getKnownTables
 
     ## PRIVATE
+       Checks if the given table name is registered in the registry.
     is_registered : Text -> Boolean
     is_registered self table_name =
         self.reference_counter.isRegistered table_name

distribution/lib/Standard/Database/0.0.0-dev/src/Internal/IR/From_Spec.enso

@@ -94,6 +94,9 @@ type From_Spec_Comparator
         _ -> Default_Comparator.compare x y
 
     ## PRIVATE
-    hash x = Default_Comparator.hash x
+    hash x = case x of
+        From_Spec.Table table_name _ _ ->
+            Default_Comparator.hash table_name
+        _ -> Default_Comparator.hash x
 
 Comparable.from (_ : From_Spec) = From_Spec_Comparator

std-bits/database/src/main/java/org/enso/database/dryrun/HiddenTableReferenceCounter.java

@@ -62,6 +62,12 @@ public synchronized void decrement(String name) {
         });
   }
 
+  /**
+   * Checks if the given table name is currently present in the registry.
+   *
+   * <p>A table is 'registered' even if its reference count has dropped to zero, as long as it has
+   * not been disposed yet.
+   */
   public synchronized boolean isRegistered(String name) {
     return tableRefCounts.containsKey(name);
   }