Graph Query Language: Difference between revisions

Revision as of 20:44, 3 November 2019

Revision as of 20:59, 3 November 2019

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Cypher allows reading, creation and updating of graph elements. The current version (including the temporal extension) is referred to as Cypher 9. Prior to the GQL project it was planned to create a new version, Cypher 10 ['''REF HEADING BELOW'''], that would incorporate features like schema and composable graph queries and views. The first designs for Cypher 10, including graph construction and projection, were implemented in the Cypher for Apache Spark project starting in 2016.<ref name="CAPS Morpheus">{{cite web|url=https://github.com/opencypher/morpheus||title=''Morpheus brings the leading graph query language, Cypher, onto the leading distributed processing platform, Spark.''|last=Rydberg|first=Mats|display-authors=etal|date=July 2016|website=|publisher=openCypher|accessdate=November 3, 2019}}</ref>These features are part of the proposed scope of GQL ['''REF TIGERGRAPH/NEO4j DOCUMENT'''].

Cypher is implemented in Neo4j's database, by Redis Graph, by Cambridge Semantics Anzograph, by Bitnine's Agens Graph, by Memgraph, and in open source projects Cypher for Gremlin<ref name="CfoG">{{cite web|url=https://github.com/opencypher/cypher-for-gremlin||title=''Cypher for Gremlin adds Cypher support to any Gremlin graph database.''|last=Novikov|first=Dmitry|display-authors=etal|date=January 2018|website=|publisher=openCypher|accessdate=November 3, 2019}}</ref> maintained by Neueda Labs in Riga, and Cypher for Apache Spark (now renamed to Morpheus)<ref> name="CAPS Morpheus"</ref><ref name="Morpheus SQL and Cypher">{{cite web|url=https://databricks.com/session/neo4j-morpheus-interweaving-table-and-graph-data-with-sql-and-cypher-in-apache-spark||title=''Neo4j Morpheus: Interweaving Table and Graph Data with SQL and Cypher in Apache Spark''|last=Green|first=Alastair|last2=Junghanns|first2=Martin|date=April 2019|website=|publisher=Databricks Inc.|accessdate=November 3, 2019}}</ref><ref name="Morpheus SQL and Cypher cont">{{cite web|url=https://databricks.com/session/neo4j-morpheus-interweaving-table-and-graph-data-with-sql-and-cypher-in-apache-spark-continues|title=''Neo4j Morpheus: Interweaving Table and Graph Data with SQL and Cypher in Apache Spark (continues)''}}</ref>, as well as in research projects such as Cypher.PL and Ingraph. Cypher as a language is governed as the openCypher project ['''REF WEBSITE, REF GITHUB ORG''']by an informal community which has held five face-to-face openCypher Implementers' Meetings since February 2017 ['''REF WEBSITE EVENTS''']

=== PGQL ===

PGQL <ref name="PGQL">{{cite web|url=http://pgql-lang.org/|title=PGQL|last=|first=|date=|website=|publisher=pgql.org|accessdate=October 6, 2019}}</ref><ref name="PGQL Grades">{{cite web|url=https://dl.acm.org/citation.cfm?id=2960421/|title=''PGQL: a property graph query language''. In Proceedings of the Fourth International Workshop on Graph Data Management Experiences and Systems (GRADES '16). ACM, New York, NY, USA, Article 7, 6 pages. DOI: 10.1145/2960414.2960421|last=van Rest|first=Oskar|display-authors=etal|date=June 2016|website=|publisher=pgql.org|accessdate=October 25, 2019}}</ref>

is a language designed and implemented by Oracle Inc., but made available as an open source specification<ref name="PGQL spec">{{cite web|url=http://pgql-lang.org/|title=PGQL|last=|first=|date=|website=|publisher=pgql.org|accessdate=October 6, 2019}}</ref>, along with JVM parsing software<ref name="PGQL parser">{{cite web|url=https://github.com/oracle/pgql-lang|title=''PGQL is an SQL-based query language for the Property Graph data model''. |last=van Rest|first=Oskar|display-authors=etal|date=September 2015|website=|publisher=pgql.org|accessdate=November 3, 2019}}</ref>. PGQL combines familiar SQL SELECT syntax including SQL expressions and result ordering and aggregation with a pattern matching language very similar to that of Cypher. It allows the specification of the graph to be queried, and includes a facility for macros to capture "pattern views". It does not support insertion or updating operations, having been designed primarily for an analytics environment, such as Oracle's PGX product. PGQL has also been implemented in Oracle Big Data Spatial and Graph, and in a research project, PGX.D/Async<ref name="PGQL PGX.D">{{cite web|url=https://dl.acm.org/citation.cfm?doid=3078447.3078454/|title=2017. ''PGX.D/Async: A Scalable Distributed Graph Pattern Matching Engine''. In Proceedings of the Fifth International Workshop on Graph Data-management Experiences & Systems (GRADES'17). ACM, New York, NY, USA, Article 7, 6 pages. DOI: 10.1145/3078447.3078454|last=Roth|first=Nicholas P.|display-authors=etal|date=|website=|publisher=ACM|accessdate=October 29, 2019}}</ref>.

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=== Cypher 10 extensions in Cypher for Apache Spark ===

The opencypher Morpheus project<ref ['''REFname="CAPS MORRPHEUS''']Morpheus"/> implements Cypher for Apache Spark users.

== References ==