15.2.1 Reading Graphs from Oracle Database into the Graph Server (PGX)

Once logged into the graph server (PGX), you can read graphs from the database into the graph server.

Your database user must exist and have read access on the graph data in the database.

The following options are supported for loading the graph:

SQL Property Graph

• Using the readGraphByName API - see Loading a SQL Property Graph Using the readGraphByName API for more details.
• Using the PgSqlSubgraphReader API to create and load a subgraph - see Loading a Subgraph Using PGQL Queries for more details.
• Using the PGQL CREATE PROPERTY GRAPH statement - see Creating a SQL Property Graph Using PGQL for more details.

Property Graph Views

• Using the readGraphByName API - see Loading a PG View Using the readGraphByName API for more details.
• Using the PGQL CREATE PROPERTY GRAPH statement - see Creating a Property Graph Using PGQL for more details.
• Using the PgViewSubgraphReader#fromPgView API to create and load a subgraph - see Loading a Subgraph from Property Graph Views for more details.
• Using a PGX graph configuration file in JSON format - see Loading a Graph Using a JSON Configuration File for more details.
• Using the GraphConfigBuilder class to create Oracle RDBMS graph configurations programmatically through Java methods - see Loading a Graph by Defining a Graph Configuration Object for more details.

Also, refer to the following sections for additional information:

• Reading Entity Providers at the Same SCN
  If you have a graph which consists of multiple vertex or edge tables or both, then you can read all the vertices and edges at the same System Change Number (SCN).
• Progress Reporting and Estimation for Graph Loading
  Loading a large graph into the graph server(PGX) can be a long running operation. However, if you load the graph using an asynchronous action, then you can monitor the progress of the graph loading operation.
• API for Loading Graphs into Memory
  Learn about the APIs used for loading a graph using a JSON configuration file or graph configuration object.
• Graph Configuration Options
  Learn about the graph configuration options.
• Data Loading Security Best Practices
  Loading a graph from the database requires authentication and it is therefore important to adhere to certain security guidelines when configuring access to this kind of data source.
• Data Format Support Matrix
  Learn about the different data formats supported in the graph server (PGX).
• Immutability of Loaded Graphs
  Once the graph is loaded into the graph server (PGX), the graph and its properties are automatically marked as immutable.