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To add to this description, the Prolog-derived syntactic core of Datalog (the Horn clauses and facts) can be viewed as a combination of "unification" and mutual
by refset 3y ago
To add to this description, the Prolog-derived syntactic core of Datalog (the Horn clauses and facts) can be viewed as a combination of "unification" and mutually recursive rules to find a fixpoint over your data+query. It's essentially like solving simultaneous equations.
The Prolog-derived syntax is routinely extended because the core is typically too simplistic/inexpressive to be directly useful, e.g. see https://www.fdi.ucm.es/profesor/fernan/des/html/manual/manualDES.html#_Toc81673921 https://www.fdi.ucm.es/profesor/fernan/des/html/manual/manua...
- convolvatron 3y agothe 'verse' language by SPJ and co explores the notion that datalog semantics can be expressed using 'normal' programs in SSA form. As long as you use pure values this works out quite well. there are some convenient normal datalog abstractions like implicit union of clauses with the same name that don't map so well. I expect this is going to show up as a really popular model at some point - don't have to have two separate worlds for queries and other logic.
- refset 3y ago> don't have to have two separate worlds for queries and other logic That's definitely the dream. Another point along that spectrum (from the author of Apache Calcite): https://github.com/hydromatic/morel https://github.com/hydromatic/morel