Examples of com.oltpbenchmark.distributions.ScrambledZipfianGenerator

com.oltpbenchmark.distributions.ScrambledZipfianGenerator
A generator of a zipfian distribution. It produces a sequence of items, such that some items are more popular than others, according to a zipfian distribution. When you construct an instance of this class, you specify the number of items in the set to draw from, either by specifying an itemcount (so that the sequence is of items from 0 to itemcount-1) or by specifying a min and a max (so that the sequence is of items from min to max inclusive). After you construct the instance, you can change the number of items by calling nextInt(itemcount) or nextLong(itemcount). Unlike @ZipfianGenerator, this class scatters the "popular" items across the itemspace. Use this, instead of @ZipfianGenerator, if you don't want the head of the distribution (the popular items) clustered together.

        String sql = SQLUtil.getInsertSQL(catalog_tbl);
        PreparedStatement tweetInsert = this.conn.prepareStatement(sql);
        
        int total = 0;
        int batchSize = 0;
        ScrambledZipfianGenerator zy = new ScrambledZipfianGenerator(this.num_users);
        
        TweetHistogram tweet_h = new TweetHistogram();
        FlatHistogram<Integer> tweet_len_rng = new FlatHistogram<Integer>(this.rng(), tweet_h);
        
        for (long i = 0; i < this.num_tweets; i++) {
            int uid = zy.nextInt();
            tweetInsert.setLong(1, i);
            tweetInsert.setInt(2, uid);
            tweetInsert.setString(3, TextGenerator.randomStr(rng(), tweet_len_rng.nextValue()));
            tweetInsert.setNull(4, java.sql.Types.DATE);
            tweetInsert.addBatch();

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        //
        int total = 0;
        int batch = 0;
        ZipfianGenerator numTrust = new ZipfianGenerator(num_trust, 1.95);
        ScrambledZipfianGenerator reviewed = new ScrambledZipfianGenerator(num_users);
        Random isTrusted = new Random(System.currentTimeMillis());
        for (int i = 0; i < num_users; i++) {
            List<Integer> trusted = new ArrayList<Integer>();
            int trust_count = numTrust.nextInt();
            for (int tc = 0; tc < trust_count;) {
                int u_id = reviewed.nextInt();
                if (!trusted.contains(u_id)) {
                    tc++;
                    trustInsert.setInt(1, i);
                    trustInsert.setInt(2, u_id);
                    trustInsert.setInt(3, isTrusted.nextInt(2));

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Related Classes of com.oltpbenchmark.distributions.ScrambledZipfianGenerator

com.oltpbenchmark.benchmarks.epinions.EpinionsLoader

com.oltpbenchmark.benchmarks.twitter.TwitterLoader

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