private void setPrev(Vector<vslIndexView<D>> prevVec) 
		throws vslInputException
	{
		if (record instanceof vslIndexUpdateRecord) {
			vslIndexUpdateRecord update = (vslIndexUpdateRecord) record;
			if (update.prev == null) {
				Vector<vslRecKey> prevKeys = new Vector<vslRecKey>();
				for (vslIndexView<D> prev: prevVec) {
					// throw exception if prev record is a delete record
					if (prev.isDelete()) {
						String err = 
							"Attempt to add an Update with a prev record that is a delete record [" 
							+ prev.getRecKey() +"]";
						vslLog.log(vslLog.ERROR, err);
						throw new vslInputException(err);
					}
					prevKeys.add(prev.getRecKey());
				}
				update.prev = prevKeys;
			}
		}
		else if (record instanceof vslIndexDeleteRecord) {
			vslIndexDeleteRecord del = (vslIndexDeleteRecord) record;
			if (del.prev == null) {
				Vector<vslRecKey> prevKeys = new Vector<vslRecKey>();
				for (vslIndexView<D> prev: prevVec) {
					// throw exception if prev record is a delete record
					if (prev.isDelete()) {
						String err = 
							"Attempt to add a Delete with a prev record that is a delete record [" 
							+ prev.getRecKey() +"]";
						vslLog.log(vslLog.ERROR, err);
						throw new vslInputException(err);
					}
					prevKeys.add(prev.getRecKey());
				}
				del.prev = prevKeys;
			}
		}
		this.prevViews = prevVec;
	}