There's a basic problem with these "database" approaches.
So you keep track of what a person bets etc. when they have a particular hand. Then you look for those bets in an attempt to discern their hand from their betting. OK.
But your target has to remember what he is "supposed" to do when he has A8 off-suit. Which, most likely, he does not. Indeed, his own hand is only part of why he bets the way he does. He is also taking into account what everybody else does. And how long they take to do it. And what they have been doing since the start of the game.
So your database is unlikely to capture all the factors he includes in his betting. He may not even be aware of exactly why he bets that way. If the guy to his right dithers over a bet or bets quickly, for example, he may change his mind without knowing exactly why. And that choice may have been influenced by the hand up to that point, or even by the previous several hands. He may have a "feel" for some of the players at the table. (Whether that "feel" is right or wrong is another matter.)
And then your target logs in with his other account where he has his big bankroll. And you don't know it's the same guy. And he cleans your clock.
Live games are even more complicated. Looking across the table and trying to decide what the other guys are holding is a thing. If you are trying to remember what he had the last time he bet that way, you are likely to miss the "tell." You are thinking "the last time he matched the blind he had a small pair" you will miss that he holds good cards in his right hand and bad cards in the left. And you won't spend the effort to kill off your own "tell."
So generally, my own personal bias is, don't bother with these database things. Learn poker, not computers. Your mileage may vary.
That being said, there is a "computing" skill you should work at. That's looking at the cards that you have seen and figuring out what hands are thereby impossible. And so working out what remaining hands could beat your hand. And also whether the hand you hope to build has been wrecked. And whether other people could reasonably guess what you were building from what is showing and how you bet. This is important in various "stud" games, Texas Holdem, and other games where cards get shown to everybody. And to some extent in "draw" games where you need to remember your discards and how they affect things.
