anchor.diff:  	      %% Handled by alter_storage_type
   	      Actions;
   	 ({ram_copies, Ns}, Actions) ->
  -	      %% Handled elsewhere
  +	      %% Handled by alter_storage_type
   	      Actions;
   	 ({disc_only_copies, Ns}, Actions) ->
   	      %% Handled by alter_storage_type
  
positive.code: %% - derive a schema from current db
  %% - verify that current db complies with schema 
  %%
  %% NOTE: looks like fragmented tables are explicitly
  %%  updated to frag status, rather than declaring them.
  %%  Thus, schematool should provide a declarative approach.
  %%
  %% UNFINISHED
  %% 1/ collect ALL of the changes in one call
  
negative.code: %%   * some options can't be changed
  %% - perform change options in appropriate order
  %%
  %% Note:
  %% - if table size = 0, we can skip some actions
  %%   * e.g., copying not needed
  %% - if table size is small, we can do different
  %%   strategy than if table is large
  %%   * small table can migrate via ram_copies
  %%
  %% UNFINISHED
  %% - what is the correct order of actions?
  %%   e.g., change table opts before or after layout, etc
  