Examples with JournalWriter com.questdb.store.JournalWriter used on opensource projects

Search in sources :

Example 16 with JournalWriter

use of com.questdb.store.JournalWriter in project questdb by bluestreak01.

the class ResamplingTest method setUp.

@BeforeClass
public static void setUp() throws Exception {
    int recordCount = 10000;
    int employeeCount = 10;
    try (JournalWriter orders = FACTORY_CONTAINER.getFactory().writer(new JournalStructure("orders").$int("orderId").$int("customerId").$int("productId").$str("employeeId").$date("orderDate").$int("quantity").$double("price").$float("rate").recordCountHint(recordCount).$())) {
        Rnd rnd = new Rnd();
        String[] employees = new String[employeeCount];
        for (int i = 0; i < employees.length; i++) {
            employees[i] = rnd.nextString(9);
        }
        long timestamp = DateFormatUtils.parseDateTime("2014-05-04T10:30:00.000Z");
        int tsIncrement = 10000;
        int orderId = 0;
        for (int i = 0; i < recordCount; i++) {
            JournalEntryWriter w = orders.entryWriter();
            w.putInt(0, ++orderId);
            w.putInt(1, rnd.nextPositiveInt() % 500);
            w.putInt(2, rnd.nextPositiveInt() % 200);
            w.putStr(3, employees[rnd.nextPositiveInt() % employeeCount]);
            w.putDate(4, timestamp += tsIncrement);
            w.putInt(5, rnd.nextPositiveInt());
            w.putDouble(6, rnd.nextDouble());
            w.putFloat(7, rnd.nextFloat());
            w.append();
        }
        orders.commit();
    }
    try (JournalWriter orders2 = FACTORY_CONTAINER.getFactory().writer(new JournalStructure("orders2").$int("orderId").$int("customerId").$int("productId").$str("employeeId").$date("orderDate").$int("quantity").$double("price").$float("rate").$date("basketDate").recordCountHint(recordCount).$())) {
        Rnd rnd = new Rnd();
        String[] employees = new String[employeeCount];
        for (int i = 0; i < employees.length; i++) {
            employees[i] = rnd.nextString(9);
        }
        long timestamp = DateFormatUtils.parseDateTime("2014-05-04T10:30:00.000Z");
        long timestamp2 = DateFormatUtils.parseDateTime("2014-05-03T00:15:00.000Z");
        int tsIncrement = 10000;
        int orderId = 0;
        for (int i = 0; i < recordCount; i++) {
            JournalEntryWriter w = orders2.entryWriter();
            w.putInt(0, ++orderId);
            w.putInt(1, rnd.nextPositiveInt() % 500);
            w.putInt(2, rnd.nextPositiveInt() % 200);
            w.putStr(3, employees[rnd.nextPositiveInt() % employeeCount]);
            w.putDate(4, timestamp += tsIncrement);
            w.putInt(5, rnd.nextPositiveInt());
            w.putDouble(6, rnd.nextDouble());
            w.putFloat(7, rnd.nextFloat());
            w.putDate(8, timestamp2 + tsIncrement);
            w.append();
        }
        orders2.commit();
    }
    try (JournalWriter orders2 = FACTORY_CONTAINER.getFactory().writer(new JournalStructure("orders4").$int("orderId").$int("customerId").$int("productId").$sym("employeeId").$date("orderDate").$int("quantity").$double("price").$float("rate").$ts("basketDate").recordCountHint(recordCount).$())) {
        Rnd rnd = new Rnd();
        String[] employees = new String[employeeCount];
        for (int i = 0; i < employees.length; i++) {
            employees[i] = rnd.nextString(9);
        }
        long timestamp = DateFormatUtils.parseDateTime("2014-05-04T10:30:00.000Z");
        long timestamp2 = DateFormatUtils.parseDateTime("2014-05-03T00:15:00.000Z");
        int tsIncrement = 10000;
        int orderId = 0;
        for (int i = 0; i < recordCount; i++) {
            JournalEntryWriter w = orders2.entryWriter();
            w.putInt(0, ++orderId);
            w.putInt(1, rnd.nextPositiveInt() % 500);
            w.putInt(2, rnd.nextPositiveInt() % 200);
            w.putSym(3, employees[rnd.nextPositiveInt() % employeeCount]);
            w.putDate(4, timestamp += tsIncrement);
            w.putInt(5, rnd.nextPositiveInt());
            w.putDouble(6, rnd.nextDouble());
            w.putFloat(7, rnd.nextFloat());
            w.putDate(8, timestamp2 + tsIncrement);
            w.append();
        }
        orders2.commit();
    }
    JournalWriter orders3 = FACTORY_CONTAINER.getFactory().writer(new JournalStructure("orders3").$int("orderId").$int("customerId").$int("productId").$str("employeeId").$int("quantity").$double("price").$float("rate").recordCountHint(recordCount).$());
    orders3.close();
}
Also used : JournalWriter(com.questdb.store.JournalWriter) JournalStructure(com.questdb.store.factory.configuration.JournalStructure) Rnd(com.questdb.std.Rnd) JournalEntryWriter(com.questdb.store.JournalEntryWriter) BeforeClass(org.junit.BeforeClass)

Example 17 with JournalWriter

use of com.questdb.store.JournalWriter in project questdb by bluestreak01.

the class SingleJournalQueryTest method testSearchByStringIdIndexed.

@Test
public void testSearchByStringIdIndexed() throws Exception {
    try (JournalWriter w = getFactory().writer(new JournalStructure("tab").$str("id").index().buckets(32).$double("x").$double("y").$ts())) {
        Rnd rnd = new Rnd();
        ObjHashSet<String> names = getNames(rnd, 1024);
        int mask = 1023;
        long t = DateFormatUtils.parseDateTime("2015-03-12T00:00:00.000Z");
        for (int i = 0; i < 100000; i++) {
            JournalEntryWriter ew = w.entryWriter();
            ew.putStr(0, names.get(rnd.nextInt() & mask));
            ew.putDouble(1, rnd.nextDouble());
            ew.putDouble(2, rnd.nextDouble());
            ew.putDate(3, t += 10);
            ew.append();
        }
        w.commit();
    }
    final String expected = "XTPNHTDCEBYWXBB\t-292.000000000000\t0.000000006354\t2015-03-12T00:00:02.290Z\n" + "XTPNHTDCEBYWXBB\t7.197236061096\t2.818476676941\t2015-03-12T00:00:27.340Z\n" + "XTPNHTDCEBYWXBB\t0.000005481412\t1.312383592129\t2015-03-12T00:00:29.610Z\n" + "XTPNHTDCEBYWXBB\t446.081878662109\t0.000000051478\t2015-03-12T00:00:31.780Z\n" + "XTPNHTDCEBYWXBB\t-809.625000000000\t0.000000104467\t2015-03-12T00:00:33.860Z\n" + "XTPNHTDCEBYWXBB\t560.000000000000\t0.526266053319\t2015-03-12T00:00:37.440Z\n" + "XTPNHTDCEBYWXBB\t0.000000004619\t0.000028377840\t2015-03-12T00:00:46.630Z\n" + "XTPNHTDCEBYWXBB\t-510.983673095703\t-512.000000000000\t2015-03-12T00:00:55.090Z\n" + "XTPNHTDCEBYWXBB\t0.000000527720\t760.000000000000\t2015-03-12T00:01:03.780Z\n" + "XTPNHTDCEBYWXBB\t0.012854952831\t-292.297058105469\t2015-03-12T00:01:09.350Z\n" + "XTPNHTDCEBYWXBB\t0.082818411291\t2.386151432991\t2015-03-12T00:01:10.310Z\n" + "XTPNHTDCEBYWXBB\t330.293212890625\t-268.000000000000\t2015-03-12T00:01:12.810Z\n" + "XTPNHTDCEBYWXBB\t278.125000000000\t0.077817678452\t2015-03-12T00:01:16.670Z\n" + "XTPNHTDCEBYWXBB\t-448.000000000000\t0.000001829988\t2015-03-12T00:02:02.260Z\n" + "XTPNHTDCEBYWXBB\t0.238381892443\t-935.843750000000\t2015-03-12T00:02:33.540Z\n" + "XTPNHTDCEBYWXBB\t0.097852131352\t-120.312500000000\t2015-03-12T00:02:41.600Z\n" + "XTPNHTDCEBYWXBB\t0.034327778034\t0.000000076055\t2015-03-12T00:02:41.860Z\n" + "XTPNHTDCEBYWXBB\t0.016777765006\t1.525665938854\t2015-03-12T00:02:47.630Z\n" + "XTPNHTDCEBYWXBB\t0.000000245470\t0.000000012355\t2015-03-12T00:03:21.880Z\n" + "XTPNHTDCEBYWXBB\t38.482372283936\t156.359012603760\t2015-03-12T00:03:25.470Z\n" + "XTPNHTDCEBYWXBB\t960.000000000000\t-561.500000000000\t2015-03-12T00:03:52.790Z\n" + "XTPNHTDCEBYWXBB\t0.000048914401\t0.000535350249\t2015-03-12T00:03:53.420Z\n" + "XTPNHTDCEBYWXBB\t0.315786086023\t-544.000000000000\t2015-03-12T00:04:02.560Z\n" + "XTPNHTDCEBYWXBB\t-512.000000000000\t512.000000000000\t2015-03-12T00:04:09.410Z\n" + "XTPNHTDCEBYWXBB\t0.000469007500\t0.000000003315\t2015-03-12T00:04:29.330Z\n" + "XTPNHTDCEBYWXBB\t473.774108886719\t0.005739651737\t2015-03-12T00:04:49.240Z\n" + "XTPNHTDCEBYWXBB\t77.079637527466\t-68.750000000000\t2015-03-12T00:04:54.540Z\n" + "XTPNHTDCEBYWXBB\t1017.250000000000\t256.000000000000\t2015-03-12T00:04:59.980Z\n" + "XTPNHTDCEBYWXBB\t979.558593750000\t0.034476440400\t2015-03-12T00:05:00.400Z\n" + "XTPNHTDCEBYWXBB\t0.080838434398\t0.000240437294\t2015-03-12T00:05:16.590Z\n" + "XTPNHTDCEBYWXBB\t837.343750000000\t0.000000003163\t2015-03-12T00:05:22.150Z\n" + "XTPNHTDCEBYWXBB\t-708.738037109375\t12.065711975098\t2015-03-12T00:05:23.960Z\n" + "XTPNHTDCEBYWXBB\t73.905494689941\t968.143554687500\t2015-03-12T00:05:30.160Z\n" + "XTPNHTDCEBYWXBB\t858.125000000000\t0.004347450798\t2015-03-12T00:06:06.300Z\n" + "XTPNHTDCEBYWXBB\t191.156250000000\t692.151489257813\t2015-03-12T00:06:07.380Z\n" + "XTPNHTDCEBYWXBB\t0.000000350446\t0.001085809752\t2015-03-12T00:06:14.550Z\n" + "XTPNHTDCEBYWXBB\t877.107116699219\t0.073764367029\t2015-03-12T00:06:26.310Z\n" + "XTPNHTDCEBYWXBB\t4.980149984360\t0.000000005301\t2015-03-12T00:06:33.470Z\n" + "XTPNHTDCEBYWXBB\t0.000937165081\t-204.000000000000\t2015-03-12T00:06:54.810Z\n" + "XTPNHTDCEBYWXBB\t756.876586914063\t-572.703125000000\t2015-03-12T00:06:56.120Z\n" + "XTPNHTDCEBYWXBB\t0.000000022885\t0.689865306020\t2015-03-12T00:06:57.920Z\n" + "XTPNHTDCEBYWXBB\t723.500000000000\t-592.817382812500\t2015-03-12T00:07:17.570Z\n" + "XTPNHTDCEBYWXBB\t-285.125000000000\t-448.250000000000\t2015-03-12T00:07:20.480Z\n" + "XTPNHTDCEBYWXBB\t4.877287983894\t-870.000000000000\t2015-03-12T00:07:36.830Z\n" + "XTPNHTDCEBYWXBB\t-638.750000000000\t-859.125000000000\t2015-03-12T00:07:38.910Z\n" + "XTPNHTDCEBYWXBB\t757.085937500000\t-128.000000000000\t2015-03-12T00:07:45.970Z\n" + "XTPNHTDCEBYWXBB\t0.000024196771\t44.254640579224\t2015-03-12T00:07:56.400Z\n" + "XTPNHTDCEBYWXBB\t0.000002050660\t113.433692932129\t2015-03-12T00:08:25.690Z\n" + "XTPNHTDCEBYWXBB\t0.001966100186\t401.331298828125\t2015-03-12T00:08:31.180Z\n" + "XTPNHTDCEBYWXBB\t134.605468750000\t0.000778750400\t2015-03-12T00:08:34.070Z\n" + "XTPNHTDCEBYWXBB\t304.000000000000\t170.421752929688\t2015-03-12T00:08:36.400Z\n" + "XTPNHTDCEBYWXBB\t0.000000029559\t0.000033108370\t2015-03-12T00:08:42.110Z\n" + "XTPNHTDCEBYWXBB\t0.064763752744\t-384.000000000000\t2015-03-12T00:08:49.670Z\n" + "XTPNHTDCEBYWXBB\t0.000000000000\t0.016534221359\t2015-03-12T00:09:01.010Z\n" + "XTPNHTDCEBYWXBB\t0.060663623735\t0.377497851849\t2015-03-12T00:09:03.830Z\n" + "XTPNHTDCEBYWXBB\t0.000001439460\t0.000000291427\t2015-03-12T00:09:05.960Z\n" + "XTPNHTDCEBYWXBB\t0.000660118021\t0.000000001520\t2015-03-12T00:09:14.030Z\n" + "XTPNHTDCEBYWXBB\t394.622238159180\t0.245789200068\t2015-03-12T00:09:35.320Z\n" + "XTPNHTDCEBYWXBB\t-1024.000000000000\t0.002625804045\t2015-03-12T00:10:04.300Z\n" + "XTPNHTDCEBYWXBB\t0.021761201322\t-805.171875000000\t2015-03-12T00:10:10.920Z\n" + "XTPNHTDCEBYWXBB\t18.621844291687\t0.003388853336\t2015-03-12T00:10:24.380Z\n" + "XTPNHTDCEBYWXBB\t-514.108642578125\t66.830410003662\t2015-03-12T00:10:30.510Z\n" + "XTPNHTDCEBYWXBB\t1.720549345016\t0.000006926386\t2015-03-12T00:10:37.250Z\n" + "XTPNHTDCEBYWXBB\t-715.183959960938\t22.427126884460\t2015-03-12T00:10:39.680Z\n" + "XTPNHTDCEBYWXBB\t0.000000000000\t0.629212051630\t2015-03-12T00:10:44.310Z\n" + "XTPNHTDCEBYWXBB\t257.433593750000\t0.000087903414\t2015-03-12T00:11:03.210Z\n" + "XTPNHTDCEBYWXBB\t0.000000070390\t-270.520019531250\t2015-03-12T00:11:18.280Z\n" + "XTPNHTDCEBYWXBB\t-439.250000000000\t0.000000093325\t2015-03-12T00:11:25.080Z\n" + "XTPNHTDCEBYWXBB\t256.000000000000\t760.565032958984\t2015-03-12T00:11:35.220Z\n" + "XTPNHTDCEBYWXBB\t634.375000000000\t0.000000033359\t2015-03-12T00:11:55.300Z\n" + "XTPNHTDCEBYWXBB\t0.000031026852\t0.000000000000\t2015-03-12T00:11:58.680Z\n" + "XTPNHTDCEBYWXBB\t90.977296829224\t0.000000124888\t2015-03-12T00:12:06.190Z\n" + "XTPNHTDCEBYWXBB\t0.845079660416\t0.000001311144\t2015-03-12T00:12:12.980Z\n" + "XTPNHTDCEBYWXBB\t-0.500000000000\t216.805793762207\t2015-03-12T00:12:28.700Z\n" + "XTPNHTDCEBYWXBB\t0.021825334989\t0.000000003128\t2015-03-12T00:12:29.420Z\n" + "XTPNHTDCEBYWXBB\t0.307688817382\t516.472656250000\t2015-03-12T00:12:36.300Z\n" + "XTPNHTDCEBYWXBB\t43.792731285095\t0.000372541021\t2015-03-12T00:12:42.040Z\n" + "XTPNHTDCEBYWXBB\t-782.687500000000\t252.748397827148\t2015-03-12T00:12:48.780Z\n" + "XTPNHTDCEBYWXBB\t137.645996093750\t808.000000000000\t2015-03-12T00:13:09.280Z\n" + "XTPNHTDCEBYWXBB\t0.002546578180\t17.097163200378\t2015-03-12T00:13:27.120Z\n" + "XTPNHTDCEBYWXBB\t-264.875000000000\t-419.750000000000\t2015-03-12T00:13:40.020Z\n" + "XTPNHTDCEBYWXBB\t0.000221305789\t53.479209899902\t2015-03-12T00:13:40.660Z\n" + "XTPNHTDCEBYWXBB\t0.030516586266\t-612.226562500000\t2015-03-12T00:13:50.440Z\n" + "XTPNHTDCEBYWXBB\t-1024.000000000000\t17.896668434143\t2015-03-12T00:13:53.350Z\n" + "XTPNHTDCEBYWXBB\t0.000000091829\t0.000000000000\t2015-03-12T00:14:06.090Z\n" + "XTPNHTDCEBYWXBB\t0.000164877347\t0.000000009079\t2015-03-12T00:14:15.960Z\n" + "XTPNHTDCEBYWXBB\t0.000000276606\t512.000000000000\t2015-03-12T00:14:31.890Z\n" + "XTPNHTDCEBYWXBB\t0.000000034906\t-1024.000000000000\t2015-03-12T00:15:19.540Z\n" + "XTPNHTDCEBYWXBB\t478.680068969727\t0.000058549787\t2015-03-12T00:15:19.790Z\n" + "XTPNHTDCEBYWXBB\t430.000000000000\t639.000000000000\t2015-03-12T00:15:33.890Z\n" + "XTPNHTDCEBYWXBB\t0.000000236331\t-960.000000000000\t2015-03-12T00:15:38.790Z\n" + "XTPNHTDCEBYWXBB\t81.210937500000\t0.000056687957\t2015-03-12T00:15:43.330Z\n" + "XTPNHTDCEBYWXBB\t648.112548828125\t0.000010239995\t2015-03-12T00:16:30.740Z\n";
    assertThat(expected, "select id, x, y, timestamp from tab where id in ('XTPNHTDCEBYWXBB')");
}
Also used : JournalWriter(com.questdb.store.JournalWriter) JournalStructure(com.questdb.store.factory.configuration.JournalStructure) Rnd(com.questdb.std.Rnd) JournalEntryWriter(com.questdb.store.JournalEntryWriter) AbstractTest(com.questdb.test.tools.AbstractTest) Test(org.junit.Test)

Example 18 with JournalWriter

use of com.questdb.store.JournalWriter in project questdb by bluestreak01.

the class SingleJournalQueryTest method createTabWithNullsAndTime.

private void createTabWithNullsAndTime() throws JournalException, NumericException {
    try (JournalWriter w = getFactory().writer(new JournalStructure("tab").$str("id").index().$str("time").$date("date"))) {
        Rnd rnd = new Rnd();
        long t = DateFormatUtils.parseDateTime("2015-03-12T00:00:00.000Z");
        for (int i = 0; i < 100; i++) {
            JournalEntryWriter ew = w.entryWriter();
            ew.putStr(0, rnd.nextBoolean() ? null : rnd.nextChars(rnd.nextPositiveInt() % 25));
            ew.putStr(1, rnd.nextPositiveInt() % 24 + ":" + rnd.nextPositiveInt() % 60);
            ew.putDate(2, t);
            ew.append();
        }
        w.commit();
    }
}
Also used : JournalWriter(com.questdb.store.JournalWriter) JournalStructure(com.questdb.store.factory.configuration.JournalStructure) Rnd(com.questdb.std.Rnd) JournalEntryWriter(com.questdb.store.JournalEntryWriter)

Example 19 with JournalWriter

use of com.questdb.store.JournalWriter in project questdb by bluestreak01.

the class SingleJournalQueryTest method testSearchUnindexedSymNull.

@Test
public void testSearchUnindexedSymNull() throws Exception {
    try (JournalWriter w = getFactory().writer(new JournalStructure("tab").$sym("id").$double("x").$double("y").$ts())) {
        Rnd rnd = new Rnd();
        ObjHashSet<String> names = getNames(rnd, 128);
        int mask = 127;
        long t = DateFormatUtils.parseDateTime("2015-03-12T00:00:00.000Z");
        for (int i = 0; i < 10000; i++) {
            JournalEntryWriter ew = w.entryWriter();
            if ((rnd.nextPositiveInt() % 10) == 0) {
                ew.putNull(0);
            } else {
                ew.putSym(0, names.get(rnd.nextInt() & mask));
            }
            ew.putDouble(1, rnd.nextDouble());
            ew.putDouble(2, rnd.nextDouble());
            ew.putDate(3, t += 10);
            ew.append();
        }
        w.commit();
    }
    assertNullSearch();
}
Also used : JournalWriter(com.questdb.store.JournalWriter) JournalStructure(com.questdb.store.factory.configuration.JournalStructure) Rnd(com.questdb.std.Rnd) JournalEntryWriter(com.questdb.store.JournalEntryWriter) AbstractTest(com.questdb.test.tools.AbstractTest) Test(org.junit.Test)

Example 20 with JournalWriter

use of com.questdb.store.JournalWriter in project questdb by bluestreak01.

the class SingleJournalQueryTest method createTabWithSymbol.

private void createTabWithSymbol() throws JournalException, NumericException {
    try (JournalWriter w = getFactory().writer(new JournalStructure("tab").$str("id").index().buckets(16).$sym("sym").$double("x").$double("y").$ts())) {
        Rnd rnd = new Rnd();
        ObjHashSet<String> names = getNames(rnd, 1024);
        ObjHashSet<String> syms = new ObjHashSet<>();
        for (int i = 0; i < 64; i++) {
            syms.add(rnd.nextString(10));
        }
        int mask = 1023;
        long t = DateFormatUtils.parseDateTime("2015-03-12T00:00:00.000Z");
        for (int i = 0; i < 10000; i++) {
            JournalEntryWriter ew = w.entryWriter();
            ew.putStr(0, names.get(rnd.nextInt() & mask));
            ew.putDouble(2, rnd.nextDouble());
            ew.putDouble(3, rnd.nextDouble());
            ew.putDate(4, t += 10);
            ew.putSym(1, syms.get(rnd.nextInt() & 63));
            ew.append();
        }
        w.commit();
    }
}
Also used : JournalWriter(com.questdb.store.JournalWriter) JournalStructure(com.questdb.store.factory.configuration.JournalStructure) Rnd(com.questdb.std.Rnd) ObjHashSet(com.questdb.std.ObjHashSet) JournalEntryWriter(com.questdb.store.JournalEntryWriter)

Aggregations

JournalWriter (com.questdb.store.JournalWriter)93 JournalStructure (com.questdb.store.factory.configuration.JournalStructure)60 JournalEntryWriter (com.questdb.store.JournalEntryWriter)59 AbstractTest (com.questdb.test.tools.AbstractTest)54 Test (org.junit.Test)52 Rnd (com.questdb.std.Rnd)42 BeforeClass (org.junit.BeforeClass)12 CountDownLatch (java.util.concurrent.CountDownLatch)9 RecordCursor (com.questdb.common.RecordCursor)6 JournalException (com.questdb.std.ex.JournalException)6 Record (com.questdb.common.Record)5 RecordSource (com.questdb.ql.RecordSource)5 Factory (com.questdb.store.factory.Factory)5 BootstrapEnv (com.questdb.BootstrapEnv)4 ServerConfiguration (com.questdb.ServerConfiguration)4 JournalLockedException (com.questdb.ex.JournalLockedException)4 ClientConfig (com.questdb.net.ha.config.ClientConfig)4 ServerConfig (com.questdb.net.ha.config.ServerConfig)4 ServerNode (com.questdb.net.ha.config.ServerNode)4 StringSink (com.questdb.std.str.StringSink)4
About Me
UseOf

Java Tutorials :

Simple Java RabbitMQ Example with Spring
Simple Springboot JPA Eclipeslink Example
Simple SpringBoot JPA Hibernate Example
Jackson JSON @JsonIgnore and @JsonIgnoreProperties Examples
Java Infinite recursion (StackOverflowError) Jackson solutions
Simple Java Jackson Serialize Objects to JSON and convert them back To Object
ElasticSearch 5 - Upload files using Java API in binary field Example
Java JAXB marshall unmarshall Examples from String and Stream
Java 8 forEach List and Map examples
ElasticSearch 5 Java API SearchRequestBuilder examples
Java ElasticSearch 5 examples with node index and mapping - running local
Convert String to int or Integer Java 8
Java 9 in action - JShell - Ubuntu
Java - removing invalid characters from a file name
Hello world!? or Hello Tutorial