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AGIndexAutomatically.java

package com.franz.agbase.examples;



import com.franz.agbase.*;



public class AGIndexAutomatically {



    /**

     * Demonstrates some basics of indexing triples automatically.

     * 

     * @param args unused

     * @throws AllegroGraphException

     */

    public static void main(String[] args) throws AllegroGraphException {

        // Connect to server, which must already be running.

        AllegroGraphConnection ags = new AllegroGraphConnection();

        try {

            ags.enable();

        } catch (Exception e) {

            throw new AllegroGraphException("Server connection problem", e);

        }



        // Set the index chunk size (in triples) -- memory is allocated in 

        // chunks as the number of triples in a store grows

        long chunkSize = ags.getChunkSize();

        System.out.println("Initial index chunk size: " + chunkSize);

        ags.setChunkSize(1000);

        System.out.println("Setting index chunk size: " + ags.getChunkSize());

        

        // Create a fresh triple store

        AllegroGraph ts = ags.renew("wilburwine", AGPaths.TRIPLE_STORES);



        // Set the unindexed triples threshold -- if the number of unindexed 

        // triples reaches this threshold, the server indexes.  Note that the

        // threshold defaults to 0, which means no automatic indexing.

        int unindexedThreshold = ts.getUnindexedThreshold();

        System.out.println("Current unindexed triples threshold: " + unindexedThreshold);

        ts.setUnindexedThreshold(500);

        System.out.println("Setting unindexed triples threshold: " + ts.getUnindexedThreshold());

        

        // Set the unmerged threshold -- when the number of unmerged index 

        // chunks reaches this threshold, the server merges them.  Note that 

        // the threshold defaults to 0, which means no automatic merging.

        int unmergedThreshold = ts.getUnmergedThreshold();

        System.out.println("Current unmerged threshold: " + unmergedThreshold);

        ts.setUnmergedThreshold(2);

        System.out.println("Setting unmerged threshold: " + ts.getUnmergedThreshold());

        

        // Load the wilburwine dataset

        String ntripleFile = AGPaths.dataSources("wilburwine.ntriples");        

        System.out.println("Loading N-Triples " + ntripleFile);

        AGLoadNtriples.loadNTriplesWithTiming(ts,ntripleFile);

        

        // Check to see if indexing occurred automatically.  The server polls 

        // every 2 seconds by default to determine if indexing or merging is

        // required.

        System.out.println("Checking to see if indexing occurred automatically.");

        System.out.println("Unmerged Chunks: " + ts.getUnmergedCount());

        System.out.println("Unindexed triples: " + ts.getUnindexedTripleCount());

        

        // Sleep for 3 seconds until the server polls and indexes

        System.out.println("Waiting 5 seconds ...");

        try {

            Thread.sleep(5000);

        } catch (Exception e) {

            System.out.println(e.getMessage());

        }

        

        // Now check again

        System.out.println("Checking again to see if indexing occurred automatically.");

        System.out.println("Unmerged Chunks: " + ts.getUnmergedCount());

        System.out.println("Unindexed triples: " + ts.getUnindexedTripleCount());

        

        // Return the server to its prior settings

        System.out.println("Returning the server to its prior settings.");

        ags.setChunkSize(chunkSize);

        ts.setUnindexedThreshold(unindexedThreshold);

        ts.setUnmergedThreshold(unmergedThreshold);

        

        // Close the triple store and disconnect from the server.

        ts.closeTripleStore();

        ags.disable();

    }



}
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