code: public void deleteShardedLinkRow(FieldDefinition linkDef, String owningObjID, int shardNumber) {
          assert linkDef.isSharded();
          assert shardNumber > 0;
          deleteRow(SpiderService.termsStoreName(linkDef.getTableDef()),
                    SpiderService.shardedLinkTermRowKey(linkDef, owningObjID, shardNumber));
      }
docs: Delete the shard row for the given sharded link and shard number.
  
  @param linkDef       {@link FieldDefinition} of a sharded link.
  @param owningObjID   ID of object that owns the link.
  @param shardNumber   Shard number of row to be deleted. Must be > 0.
  @see                 #addShardedLinkValue(String, FieldDefinition, DBObject, int)
  @see                 SpiderService#shardedLinkTermRowKey(FieldDefinition, String, int)