java heap analysis with oql: Count unique strings

Question

Im doing a memory analysis of an existing java software. Is there a sql \'group by\' equivalent in oql to see the count of objects with same values but different instances.<

Answer 1

A far more efficient query:

var countByValue = {};

// Scroll the strings
heap.forEachObject(
  function(strObject) {
    var key = strObject.toString();
    var count = countByValue[key];
    countByValue[key] = count ? count + 1 : 1;
  },
  "java.lang.String",
  false
);

// Transform the map into array
var mapEntries = [];
for (var i = 0, keys = Object.keys(countByValue), total = keys.length; i < total; i++) {
  mapEntries.push({
    count : countByValue[keys[i]],
    string : keys[i]
  });
}

// Sort the counts
sort(mapEntries, 'rhs.count - lhs.count');