15.2.1.2 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.

The following table shows the asynchronous graph loading APIs supported for the following formats:

Table 15-3 Asynchronous Graph Loading APIs

Data Format	API
PG VIEWS	session.readGraphByNameAsync()
PG SCHEMA	session.readGraphWithPropertiesAsync()
CSV	session.readGraphFileAsync()

These supported APIs return a PgxFuture object.

You can then use the PgxFuture.getProgress() method to collect the following statistics:

• Report on the progress of the graph loading operation
• Estimate of the remaining vertices and edges that need to be loaded into memory

For example, the following code shows the steps to load a PG view graph asynchronously and subsequently obtain the FutureProgress object to report and estimate the loading progress. However, note that the graph loading estimate (for example, the number of loaded entities and providers or the number of total entities and providers) can be obtained only until the graph loading operation is in progress. Also, the system internally computes the graph loading progress for every 10000 entries of entities that are loaded into the graph server (PGX).

• JShell
• Java

opg4j>  var graphLoadingFuture = session.readGraphByNameAsync("BANK_GRAPH_VIEW", GraphSource.PG_VIEW)
readGraphFuture ==> oracle.pgx.api.PgxFuture@6106dfb6[Not completed]

opg4j> while (!graphLoadingFuture.isDone()) {
...>   var progress = graphLoadingFuture.getProgress();
...>   var graphLoadingProgress = progress.asGraphLoadingProgress();
...>   if (graphLoadingProgress.isPresent()) {
...>     var numLoadedVertices = graphLoadingProgress.get().getNumLoadedVertices();
...>   }
...>   Thread.sleep(1000);
...> }

opg4j> var graph = graphLoadingFuture.get();
graph ==> PgxGraph[name=BANK_GRAPH_VIEW_3,N=999,E=4993,created=1664289985985]

PgxFuture<PgxGraph> graphLoadingFuture = session.readGraphByNameAsync("BANK_GRAPH_VIEW", GraphSource.PG_VIEW);
while (!graphLoadingFuture.isDone()) {
  FutureProgress progress = graphLoadingFuture.getProgress();
  Optional < GraphLoadingProgress > graphLoadingProgress = progress.asGraphLoadingProgress();
  if (graphLoadingProgress.isPresent()) {
    long numLoadedVertices = graphLoadingProgress.get().getNumLoadedVertices();
  }
  Thread.sleep(1000);
}
PgxGraph graph = graphLoadingFuture.get();

It is recommended that you do not use the FutureProgress object in a chain of asynchronous operations.