Changes in This Release for This Guide

The following changes apply to property graph support that is shipped with Oracle Graph Server and Client.

Oracle Graph Server and Client is required for using the property graph feature of Oracle Database (see section 1.2), and is released four times a year.

New Features

Significant New Features in Oracle Graph Server and Client 21.1

• PgxML Library: Support for new graph-based machine learning algorithms:
  • DeepWalk, Supervised GraphWise and Pg2vec
  • Ability to store trained models and embeddings in the Oracle Database

  See Using the Machine Learning Library (PgxML) for Graphs for more information.

• Define property graph views on Oracle Database tables and query them using PGQL.

  See Property Graph Views on Oracle Database Tables for more information.

• Enhanced graph server authentication security and user experience:
  • Better auditability of authorization changes by storing graph server permission mappings in the Oracle Database
  • Auto-renewal of authentication tokens with automatic re-authentication upon renewal
  • Added API to easily re-authenticate when maximum amount of auto-renewals is reached

  See User Authentication and Authorization for more information.

  See Upgrading From Graph Server and Client 20.4.x to 21.1.0 for more information on migrating authorization rules if you are migrating from Graph Server and Client 20.4.x to 21.1.0.

• Secured communication between graph server (PGX) and client is enforced using TLS.

  See Self-signed TLS certificate now generated upon RPM installation for more details.

Significant New Features in Oracle Graph Server and Client 20.4

• Use CREATE PROPERTY GRAPH statement to create a graph from tables in the database and make it available in the in-memory graph server (PGX)
• Python client for the in-memory graph server (PGX)
• Zeppelin 0.9 (Zeppelin 0.8 is no longer supported)
• Use database credentials to log into graph visualization tool

Significant new features in earlier Oracle Graph Server and Client releases include:

• Graph Visualization tool: Lightweight, single-page web application to visualize graphs.
• In-memory graph representation optimization for reduced memory usage and faster performance.
• User-defined functions (UDFs), for creating custom graph algorithms and extending product graph algorithms with Java or JavaScript syntax.
• Support for Autonomous Database.
• Graph server authentication and authorization based on Oracle Database users and roles.
• New Synchronizer API to keep partitioned graphs up-to-date with changes in the Oracle Database.
• PGQL features:
  • Added a CREATE PROPERTY GRAPH statement to both PGQL on Oracle Database and PGQL on PGX for creating property graphs from existing tables
  • Added support for CHEAPEST and TOP k CHEAPEST path queries to PGQL on Graph Server (PGX).

    Note:

    This support does not apply for PGQL queries executed directly against graph in Oracle Database.
  • Implemented the PGQL 1.3 language specification, which can be found at https://pgql-lang.org/
  • Added support for INSERT, UPDATE, and DELETE queries
  • Added support for MATCH inside FROM, and optional ON clauses
  • Added support for case insensitivity
  • Added support for quoted identifiers
  • Added support for subqueries after GROUP BY
  • Added a PGQL plugin for SQLcl
  • New built-in algorithms:
    • Compute High Degree Vertices
    • Create Distance Index
    • Limited Shortest Path (Hop Distance)
    • All Reachable Vertices/Edges
    • Louvain (community detection)
    • Python client for PGX

Migrating Property Graph Applications to Oracle Database 21c

From Release 21c onwards, Oracle Graph Server and Client must be installed separately. It is recommended to remove the older property graph libraries from $ORACLE_HOME. See Uninstalling Previous Versions of Property Graph Libraries for more details.

Deprecated Features

• PL/SQL API OPG_APIS.GET_SCN Function
  The PL/SQL API OPG_APIS.GET_SCN function is deprecated. Instead, to retrieve the current SCN (system change number), use the DBMS_FLASHBACK.GET_SYSTEM_CHANGE_NUMBER function:

  SELECT dbms_flashback.get_system_change_number FROM DUAL;

• Two-Table Support

  Support for the two-table format described in Handling Property Graphs Using a Two-Tables Schema was deprecated in 19c and will be removed in a future release.

• Apache Tinkerpop API Support

  Apache Tinkerpop API support for Oracle Database was deprecated in 19c and is scheduled to be removed in a future release.

• OraclePgqlResultSet

  The oracle.pg.rdbms.OraclePgqlResultSet interface was deprecated in 19c and will be removed in a future release. Instead, use the standardized interface oracle.pgql.lang.ResultSet to retrieve values from a PGQL result set.

Desupported Features

• Graph property text search based on Apache Solr/Lucene is desupported. Instead, use Oracle Text or PGQL query expressions.
• The PGX property type DATE is desupported. Instead, use LOCAL_DATE or TIMESTAMP.
• Support for the Apache Groovy-based shell was deprecated in 19c and is now desupported.