>> Most Prologs do something approximating a naive depth-first search with unification, and on complex search problems this approach rapidly blows up.
Most modern Prologs use indexing on predicates' symbols and arguments to speed up queries and the days when Prolog was a "slow" language are long gone by.
As to the search strategy, it's a bog-standard, depth-first search (no approximation). Unification is part of the theorem-proving algorith, SLD-resolution. Depth-first search is used to find "resolvents", i.e. candidates for resolution (ish).
The parent post describes a backward-chaining problem, where rules must be selected depending on their arguments, most likelly to perform some complex reasoning procedure. In that context, search is required to select relevant rules at each step of the reasoning process- not, say, to search a large database for all records of persons with a name starting from "m".
For this kind of use-case, Prolog's search is not only perfectly adequate, but also nearly perfectly optimised, due to long years of development as a language.
That said, "searching a database for all records starting from m" is very much like searching for resolvents and thanks to modern practices, like indexing, Prolog can do that kind of search just fine also.
Most modern Prologs use indexing on predicates' symbols and arguments to speed up queries and the days when Prolog was a "slow" language are long gone by.
As to the search strategy, it's a bog-standard, depth-first search (no approximation). Unification is part of the theorem-proving algorith, SLD-resolution. Depth-first search is used to find "resolvents", i.e. candidates for resolution (ish).
The parent post describes a backward-chaining problem, where rules must be selected depending on their arguments, most likelly to perform some complex reasoning procedure. In that context, search is required to select relevant rules at each step of the reasoning process- not, say, to search a large database for all records of persons with a name starting from "m".
For this kind of use-case, Prolog's search is not only perfectly adequate, but also nearly perfectly optimised, due to long years of development as a language.
That said, "searching a database for all records starting from m" is very much like searching for resolvents and thanks to modern practices, like indexing, Prolog can do that kind of search just fine also.