As graph databases become widespread, JTC1 -- the committee in joint charge
of information technology standards for the International Organization for
Standardization (ISO), and International Electrotechnical Commission (IEC) --
has approved a project to create GQL, a standard property graph query language.
This complements a project to extend SQL with a new part, SQL/PGQ, which
specifies how to define graph views over an SQL tabular schema, and to run
read-only queries against them.
Both projects have been assigned to the ISO/IEC JTC1 SC32 working group for
Database Languages, WG3, which continues to maintain and enhance SQL as a
whole. This common responsibility helps enforce a policy that the identical
core of both PGQ and GQL is a graph pattern matching sub-language, here termed
GPML.
The WG3 design process is also analyzed by an academic working group, part of
the Linked Data Benchmark Council (LDBC), whose task is to produce a formal
semantics of these graph data languages, which complements their standard
specifications.
This paper, written by members of WG3 and LDBC, presents the key elements of
the GPML of SQL/PGQ and GQL in advance of the publication of these new
standards
