4.5.1 Creating a JSON Configuration to Load a Graph

Loading a Graph from the Property Graph Schema Using JSON Configuration

The graph server (PGX) allows the loading of property graphs from Oracle Database using the property graph schema.

You can create a graph configuration file to load the graph. The following shows a sample graph configuration file that uses a keystore to connect to the database. See Store the Database Password in a Keystore for more information on using a keystore.

{
  "name": "BANK_ACCOUNTS",
  "format": "pg",
  "db_engine": "rdbms",
  "jdbc_url": "jdbc:oracle:thin:@localhost:1521/orclpdb",
  "username":"graphuser",
  "keystore_alias":"database1",
  "vertex_props": [
    {
      "name": "ID",
      "type": "integer"
    },
    {
      "name": "NAME",
      "type": "string"
    }
  ],
  "edge_props": [
    {
      "name": "AMOUNT",
      "type": "float"
    },
    {
      "name": "DESCRIPTION",
      "type": "string"
    }
  ],
  "partition_while_loading": "by_label",
  "loading":{
    "load_edge_label":true,
    "load_vertex_labels": true,
    "create_vertex_id_mapping": true,
    "create_edge_id_mapping": true
  }
}

See API for Loading Graphs into Memory for more information on PgxSession API methods for reading graphs into memory.

You can now read the graph into the graph server (PGX) using the PgxSession API method as shown:

• JShell
• Java
• Python

opg4j> var g = session.readGraphWithProperties("bank_graph.json")

PgxGraph g = session.readGraphWithProperties("bank_graph.json");

g = session.read_graph_with_properties("bank_graph.json")

Loading a Partitioned Graph Using JSON Configuration

In order to load a partitioned graph into the graph server (PGX), you can create a graph configuration file, which contains metadata about the graph to be loaded.

The following shows a sample partitioned graph configuration file:

{
  "name": "bank_graph_analytics",
  "vertex_providers":[
        {
            "name":"Accounts",
            "format":"rdbms",
            "database_table_name":"BANK_NODES",
            "key_column":"ID",
            "key_type": "integer"
        }
    ],
    "edge_providers":[
        {
            "name":"Transfers",
            "format":"rdbms",
            "database_table_name":"BANK_EDGES_AMT",
            "key_column":"ID",
            "source_column":"SRC_ID",
            "destination_column":"DEST_ID",
            "source_vertex_provider":"Accounts",
            "destination_vertex_provider":"Accounts",
            "props":[
                {
                        "name":"TXN_AMT",
                        "type":"float",
                        "column":"AMOUNT"
                }
            ]
        }
    ]
}

In the preceding configuration file, the edge property AMOUNT is renamed to TXN_AMT. This implies that you can rename vertex or edge properties when loading a graph in to the graph server (PGX) to have different names than the names of the underlying columns in the database.

See Graph Configuration Options for more details on partitioned graph configuration options.

You can now read the graph into the graph server as shown:

• JShell
• Java
• Python

opg4j> var g = session.readGraphWithProperties("bank_graph_analytics.json")

PgxGraph g = session.readGraphWithProperties("bank_graph_analytics.json");

g = session.read_graph_with_properties("bank_graph_analytics.json")