Added lab experiment to check H2 MVStore perf

tools_scripts/lab/h2MVStoreTest.groovy

@@ -0,0 +1,44 @@
+@Grab(group='com.h2database', module='h2-mvstore', version='1.4.192')
+import org.h2.mvstore.*
+
+def fileName = "mvtest.h2"
+if (args.size() == 1) {
+    fileName = args[1]
+}
+MVStore s = MVStore.open(fileName)
+// create/get the map named "data"
+MVMap<Integer, String> map = s.openMap("data")
+
+numMessages = 10000000
+
+println "Created store and starting"
+long start = System.currentTimeMillis()
+(1..numMessages).each {
+    String randomContent = UUID.randomUUID().toString()
+    // add and read some data
+    map.put(it, randomContent)
+}
+long stop = System.currentTimeMillis()
+long contentSize = UUID.randomUUID().toString().bytes.length
+println "Wrote $numMessages keys, ${numMessages * contentSize} bytes in ${stop - start} ms"
+def writeSpeed = (numMessages * contentSize)/((stop - start)/ 1000)
+println "Speed is: $writeSpeed byte/sec"
+
+// close the store (this will persist changes)
+s.close()
+
+//The read part
+
+map = MVStore.open(fileName).openMap("data")
+//read now 10M keys
+start = System.currentTimeMillis()
+(1..numMessages).each {
+    int key = (int) Math.floor(Math.random() * numMessages) + 1
+    // add and read some data
+    String randomContent = map.get(key)
+}
+
+stop = System.currentTimeMillis()
+println "Read $numMessages keys, ${numMessages * contentSize} bytes in ${stop - start} ms"
+def readSpeed = (numMessages * contentSize)/((stop - start)/ 1000)
+println "Read speed is: $readSpeed byte/sec"