There is a movement afoot to develop GQL as a kind of SQL for graphs. It's
just starting up, and I'm afraid that they may create YAK (Yet Another
Kluge). But since they want to use SQL conventions, there is a possibility
for making it compatible with DOL. If they do that, it could be a winner.
Otherwise, it could be a disaster.
The header of SQL is neutral: SELECT ... WHERE /* A statement in some
version of logic */
My recommendation is to base the WHERE-clause on DOL, which is an OMG
standard that can relate all the logics of the Semantic Web and all the
diagrams of Formal UML to Common Logic.
In March of 2020, I presented a talk at the Knowledge Graph conference,
for which I got the best presentation award. I updated it for a keynote
speech at the European Semantic Web Conference in June 2020. In both
talks, I emphasized the importance of interoperability and the use of DOL
for relating all the logics to one another via the freely available
software that was available. See
http://jfsowa.com/talks/eswc.pdf .
In eswc.pdf, I emphasized the relationship of graph logics to Common Logic
and the OMG standard for DOL. I believe that approach could be used to
allow any logic supported by DOL as a candidate for the WHERE clause. That
would include a broad range of logics that are already being used plus any
new logics that could be mapped to and from graphs. As examples, I used
existential graphs and conceptual graphs. They are general enough to
include all the current knowledge graphs as proper subsets -- and both EGs
and CGs can support the same version of Common Logic as DOL they can also
be extended to support IKL -- but that would not be in the first version of
GQL.
Some people might complain that Common Logic is too powerful. But DOL
supports mappings among a very wide range of logics from the simplest up to
some very rich versions. A standard based on DOL would allow and encourage
implementers to choose any level of expressive power that any DOL logic
supports.
That would allow implementers to start small and add as much expressive
power as they find useful at any time they wish And it would show them an
open-ended growth path for the future.
Bottom Line: The standards organizations have a motto: "Standards should
be built on other standards." By building GQL on DOL, they would create a
bridge to all the logics of the Semantic Web, Formal UML, and SQL, which
supports a subset of first-order logic.
John