anchor.diff:  %% Number of snapshots to keep after GC
   -define(SNAPSHOT_MIN, 3).
   %% Number of ops to keep before GC
  --define(OPS_THRESHOLD, 25).
  +-define(OPS_THRESHOLD, 50).
   %% The first 3 elements in operations list are meta-data
   %% First is the key
   %% Second is a tuple {current op list size, max op list size}
  
positive.code: 
  %% API
  -export([start_vnode/1,
  	       check_tables_ready/0,
           read/7,
  	       get_cache_name/2,
  	       store_ss/3,
           update/2,
  	       belongs_to_snapshot_op/3]).
  
  %% Callbacks
  -export([init/1,
  
negative.code: 		 [{_, SnapshotDict}] ->
  		     case vector_orddict:get_smaller(MinSnapshotTime, SnapshotDict) of
  			 {undefined, _IsF} ->
  			     {error, no_snapshot};
  			 {{SCT, LS},IsF}->
  			     {LS,SCT,IsF}
  