...became popular through the work of Eugene Nalimov, who calculated all possible positions with 5 pieces or less on the board (king + king + 3 other pieces). For each of the legal positions he wrote into a data base if it was won, lost or drawn.
Unfortunately, the resulting amount of data is enormous. For 5 pieces you need about 7000 MB of disk space (download here). To store all chess positions (up to 32 pieces) one would need a data base that can hold about as much positions as there are atoms in the known universe, hence such a memory bank is unlikely to be ever constructed. In addition, there is not enough time to calculate all these positions.
You can install Nalimov's table bases which will slightly improve Aristarch’s play in late end games. Be sure to install a complete set of tablebases (7000 MB for the 5-stone, or 30 MB for the 4-stone), as an incomplete one can easily decrease Aristarch’s playing strength drastically (worse than using no table bases at all). You can use the tool Wilhelm to check if you have complete tablebases or which are missing.
Table bases provide perfect knowledge for late end games. If one had table bases not only for 5 pieces, but for all chess positions, one would have the perfect playing chess engine. True or not true?
The decision about what is the best move is also dependent on the opponent. Probably the beginning position in chess is a draw, so the only way to win is to make moves that make it difficult for the opponent to find the move that stays in a draw. (You can only win if your opponent makes a mistake.) Therefore with perfect chess knowledge, you could of course always draw, but not necessarily win against good players (because the engine does not put the opponent under pressure and plays aimless).
This is already important in end games, for example the engine must not exchange its queen in a drawn KQ-KR but strive for positions that are difficult to handle for the opponent. Also, it is a known problem in the checkers program "Chinook".
So, perfect chess knowledge does not solve the problem to make "active" moves that put the opponent under pressure. To win makes it necessary to know and take advantage of the specific weaknesses of the opponent. The current problem of chess programs is that they only have a general strategy, but do not know who their opponents are and cannot adapt to them (Deep Blue was adapted manually to Kasparov).
Hence, my personal opinion is that a human world champion who gets the possibility to study a computer opponent thoroughly, will not lose against it in the foreseeable future (provided that the developers do not change the engine between the games). A chess engine is nothing more than a static, unchangable rule which is applied to a given chess position. The human mind can learn and adapt.
Today's chess engines work by searching through all possible lines in a given position. One could think that it may be possible to find a rule that simply tells which move is the correct one, without having to search in the dark. Unfortunately, this cannot be true for two reasons: