Cleanup and minor changes

engine/table/src/main/java/io/deephaven/engine/table/impl/PartitionAwareSourceTable.java

@@ -205,7 +205,6 @@ protected final Table redefine(TableDefinition newDefinitionExternal, TableDefin
  reference, null, viewColumns, null);
  }
 
- private static final String LOCATION_KEY_COLUMN_NAME = "__PartitionAwareSourceTable_TableLocationKey__";
  private static final String TRACKED_KEY_COLUMN_NAME = "__PartitionAwareSourceTable_TrackedTableLocationKey__";
 
  private static <T> ColumnSource<? super T> makePartitionSource(@NotNull final ColumnDefinition<T> columnDefinition,
@@ -236,15 +235,13 @@ protected final Collection<TrackedTableLocationKey> filterLocationKeys(
  // TODO (https://github.com/deephaven/deephaven-core/issues/867): Refactor around a ticking partition table
  final List<String> partitionTableColumnNames = Stream.concat(
  partitioningColumnDefinitions.keySet().stream(),
- Stream.of(LOCATION_KEY_COLUMN_NAME, TRACKED_KEY_COLUMN_NAME)).collect(Collectors.toList());
+ Stream.of(TRACKED_KEY_COLUMN_NAME)).collect(Collectors.toList());
  final List<ColumnSource<?>> partitionTableColumnSources =
  new ArrayList<>(partitioningColumnDefinitions.size() + 1);
  for (final ColumnDefinition<?> columnDefinition : partitioningColumnDefinitions.values()) {
  partitionTableColumnSources.add(makePartitionSource(columnDefinition, immutableTableLocationKeys));
  }
- // Add the tracked and immutable keys to the table
- partitionTableColumnSources.add(ArrayBackedColumnSource.getMemoryColumnSource(immutableTableLocationKeys,
- ImmutableTableLocationKey.class, null));
+ // Add the tracked keys to the table
  partitionTableColumnSources.add(ArrayBackedColumnSource.getMemoryColumnSource(foundLocationKeys,
  TrackedTableLocationKey.class, null));
 
@@ -255,7 +252,7 @@ protected final Collection<TrackedTableLocationKey> filterLocationKeys(
  return foundLocationKeys;
  }
 
- // Return the filtered tracked location keys
+ // Return the filtered keys
  final Iterable<TrackedTableLocationKey> iterable =
  () -> filteredColumnPartitionTable.columnIterator(TRACKED_KEY_COLUMN_NAME);
  return StreamSupport.stream(iterable.spliterator(), false).collect(Collectors.toList());

engine/table/src/main/java/io/deephaven/engine/table/impl/SourceTable.java

@@ -163,12 +163,7 @@ private void maybeAddLocations(@NotNull final Collection<TrackedTableLocationKey
  }
  filterLocationKeys(locationKeys)
  .parallelStream()
- .forEach(lk -> {
- // Unconditionally manage all locations added to the column source manager
- final TableLocation tableLocation = locationProvider.getTableLocation(lk.getKey());
- columnSourceManager.manage(tableLocation);
- columnSourceManager.addLocation(tableLocation);
- });
+ .forEach(lk -> columnSourceManager.addLocation(locationProvider.getTableLocation(lk.getKey())));
  }
 
  private TrackedTableLocationKey[] maybeRemoveLocations(

engine/table/src/main/java/io/deephaven/engine/table/impl/locations/impl/AbstractTableLocationProvider.java

@@ -125,6 +125,7 @@ protected void destroy() {
  AbstractTableLocationProvider.this.destroy();
  }
  };
+ // TODO: understand why this seems to be needed
  LivenessScopeStack.peek().manage(livenessNode);
  }
 

engine/table/src/main/java/io/deephaven/engine/table/impl/locations/impl/SingleTableLocationProvider.java

@@ -26,7 +26,7 @@ public final class SingleTableLocationProvider implements TableLocationProvider
  public SingleTableLocationProvider(@NotNull final TableLocation tableLocation) {
  this.tableLocation = tableLocation;
  trackedTableLocationKey = new TrackedTableLocationKey(tableLocation.getKey(), ttlk -> {
- // no-op
+ // TODO: I don't think we need to do anything here, but need to think more about it
  });
  }
 

engine/table/src/main/java/io/deephaven/engine/table/impl/sources/regioned/RegionedColumnSourceManager.java

@@ -230,6 +230,8 @@ public synchronized void addLocation(@NotNull final TableLocation tableLocation)
  if (log.isDebugEnabled()) {
  log.debug().append("LOCATION_ADDED:").append(tableLocation.toString()).endl();
  }
+ // Hold on to this table location.
+ manage(tableLocation);
  emptyTableLocations.add(new EmptyTableLocationEntry(tableLocation));
  } else {
  // Duplicate location - not allowed