10.2 Loading a Graph Using a JSON Configuration File

To load a PGQL property graph into the graph server (PGX), you can create a graph configuration file, which contains the graph metadata to be loaded.

The following shows a sample JSON configuration file:

{
  "name": "BANK_GRAPH",
  "source_name": "BANK_GRAPH",
  "source_type": "pg_pgql",
  "jdbc_url":"jdbc:oracle:thin:@localhost:1521/orclpdb",
  "username":"graphuser",
  "keystore_alias":"database1",
  "vertex_providers":[
        {
            "name":"Accounts",
            "format":"rdbms",
            "database_table_name":"BANK_ACCOUNTS",
            "key_column":"ID",
            "key_type": "integer",
            "parallel_hint_degree": 3,
             "props":[
                {
                        "name":"ID",
                        "type":"integer"

                },
                 {
                        "name":"NAME",
                        "type":"string"
                 }

            ]


        }
    ],
    "edge_providers":[
        {
            "name":"Transfers",
            "format":"rdbms",
            "database_table_name":"BANK_TXNS",
            "key_column":"ID",
            "parallel_hint_degree": 3,
            "source_column":"FROM_ACCT_ID",
            "destination_column":"TO_ACCT_ID",
            "source_vertex_provider":"Accounts",
            "destination_vertex_provider":"Accounts",
            "props":[
                {
                        "name":"FROM_ACCT_ID",
                        "type":"integer"
                },
                {
                        "name":"TXN_AMOUNT",
                        "type":"float",
                        "column":"AMOUNT"
                },
                {
                        "name":"DESCRIPTION",
                        "type":"string"
                },
                {
                        "name":"TO_ACCT_ID",
                        "type":"integer"
                }
            ]
        }
    ]
}

The preceding configuration uses a Java keystore alias to reference the database password that is stored in a keystore file. See Store the Database Password in a Keystore for more information.

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

See Also:

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

./bin/opg4j --secret_store /etc/oracle/graph/keystore.p12
enter password for keystore /etc/oracle/graph/keystore.p12:
For an introduction type: /help intro
Oracle Graph Server Shell 24.4.0
Variables instance, session, and analyst ready to use
opg4j> var g = session.readGraphWithProperties("<path_to_json_configuration>")
g ==> PgxGraph[name=BANK_GRAPH_NEW,N=999,E=4993,created=1675960224397]
ServerInstance instance = GraphServer.getInstance("https://localhost:7007", <username>, <password>.toCharArray());
PgxSession session = instance.createSession("my-session");
String keystorePath = "/etc/oracle/graph/keystore.p12";
char[] keystorePassword = "<keystore_password>".toCharArray();
session.registerKeystore(keystorePath, keystorePassword);
PgxGraph g = session.readGraphWithProperties("<path_to_json_configuration>");
System.out.println("Graph: " + g);

Parent topic: Loading a PGQL property graph into the Graph Server (PGX)

10.2.1 Configuring PARALLEL Hint when Loading a Graph

You can also optimize the graph loading performance by configuring a specific parallel hint value using the GraphConfig field, PARALLEL_HINT_DEGREE, which will be used by the underlying SQL queries. This can be applied when loading a graph using a JSON configuration file or through the GraphConfigBuilder API.

The following table describes how the internal queries are configured based on the specified PARALLEL_HINT_DEGREE values.

Table 10-2 PARALLEL_HINT_DEGREE values

PARALLEL_HINT_DEGREE Value Parallel hint used in the SQL Statement
Positive integer(n) Uses the given n degree:

SELECT /*+ PARALLEL(n) */ ...
Zero Uses a plain hint:

SELECT /*+ PARALLEL */ ...
Negative integer

(Default value: -1)

No PARALLEL hint:

SELECT ...

See Also:

Parent topic: Loading a Graph Using a JSON Configuration File