diff --git a/benchmarks/commonUtilities.js b/benchmarks/commonUtilities.js
index 7224ef5..d4461f4 100644
--- a/benchmarks/commonUtilities.js
+++ b/benchmarks/commonUtilities.js
@@ -154,7 +154,8 @@ module.exports.updateDocs = function (options, d, n, profiler, cb) {
       return cb();
     }
 
-    d.update({ docNumber: order[i] }, { newDocNumber: i }, options, function (err, nr) {
+    // Will not actually modify the document but will take the same time
+    d.update({ docNumber: order[i] }, { docNumber: order[i] }, options, function (err, nr) {
       if (nr !== 1) { return cb('One update didnt work'); }
       executeAsap(function () {
         runFrom(i + 1);
diff --git a/benchmarks/insert.js b/benchmarks/insert.js
index e10797c..86ba8ce 100644
--- a/benchmarks/insert.js
+++ b/benchmarks/insert.js
@@ -21,7 +21,6 @@ console.log("Test with " + n + " documents");
 console.log(program.withIndex ? "Use an index" : "Don't use an index");
 console.log("----------------------------");
 
-
 async.waterfall([
   async.apply(commonUtilities.prepareDb, benchDb)
 , function (cb) {
diff --git a/benchmarks/remove.js b/benchmarks/remove.js
index b07eda0..4c8f5d4 100644
--- a/benchmarks/remove.js
+++ b/benchmarks/remove.js
@@ -7,14 +7,33 @@ var Datastore = require('../lib/datastore')
   , execTime = require('exec-time')
   , profiler = new execTime('REMOVE BENCH')
   , d = new Datastore(benchDb)
-  , n = 10000
+  , program = require('commander')
+  , n
   ;
 
-if (process.argv[2]) { n = parseInt(process.argv[2], 10); }
+program
+  .option('-n --number [number]', 'Size of the collection to test on', parseInt)
+  .option('-i --with-index', 'Test with an index')
+  .parse(process.argv);
+
+n = program.number || 10000;
+
+console.log("----------------------------");
+console.log("Test with " + n + " documents");
+console.log(program.withIndex ? "Use an index" : "Don't use an index");
+console.log("----------------------------");
 
 async.waterfall([
   async.apply(commonUtilities.prepareDb, benchDb)
-, function (cb) { d.loadDatabase(cb); }
+, function (cb) {
+    d.loadDatabase(function (err) {
+      if (err) { return cb(err); }
+      if (program.withIndex) {
+        d.ensureIndex({ fieldName: 'docNumber' });
+      }
+      cb();
+    });
+  }
 , function (cb) { profiler.beginProfiling(); return cb(); }
 , async.apply(commonUtilities.insertDocs, d, n, profiler)
 
diff --git a/benchmarks/update.js b/benchmarks/update.js
index de71348..e27e009 100644
--- a/benchmarks/update.js
+++ b/benchmarks/update.js
@@ -7,14 +7,33 @@ var Datastore = require('../lib/datastore')
   , execTime = require('exec-time')
   , profiler = new execTime('UPDATE BENCH')
   , d = new Datastore(benchDb)
-  , n = 10000
+  , program = require('commander')
+  , n
   ;
 
-if (process.argv[2]) { n = parseInt(process.argv[2], 10); }
+program
+  .option('-n --number [number]', 'Size of the collection to test on', parseInt)
+  .option('-i --with-index', 'Test with an index')
+  .parse(process.argv);
+
+n = program.number || 10000;
+
+console.log("----------------------------");
+console.log("Test with " + n + " documents");
+console.log(program.withIndex ? "Use an index" : "Don't use an index");
+console.log("----------------------------");
 
 async.waterfall([
   async.apply(commonUtilities.prepareDb, benchDb)
-, function (cb) { d.loadDatabase(cb); }
+, function (cb) {
+    d.loadDatabase(function (err) {
+      if (err) { return cb(err); }
+      if (program.withIndex) {
+        d.ensureIndex({ fieldName: 'docNumber' });
+      }
+      cb();
+    });
+  }
 , function (cb) { profiler.beginProfiling(); return cb(); }
 , async.apply(commonUtilities.insertDocs, d, n, profiler)
 
diff --git a/lib/datastore.js b/lib/datastore.js
index c2188b0..c7369bc 100644
--- a/lib/datastore.js
+++ b/lib/datastore.js
@@ -340,6 +340,7 @@ Datastore.prototype._update = function (query, updateQuery, options, cb) {
     , numReplaced = 0
     , multi, upsert
     , updatedDocs = []
+    , candidates
     , i
     ;
 
@@ -367,12 +368,14 @@ Datastore.prototype._update = function (query, updateQuery, options, cb) {
     });
   }
   , function () {   // Perform the update
+    candidates = self.getCandidates(query)
+
     try {
-      for (i = 0; i < self.data.length; i += 1) {
-        if (model.match(self.data[i], query) && (multi || numReplaced === 0)) {
+      for (i = 0; i < candidates.length; i += 1) {
+        if (model.match(candidates[i], query) && (multi || numReplaced === 0)) {
           numReplaced += 1;
-          self.data[i] = model.modify(self.data[i], updateQuery);
-          updatedDocs.push(self.data[i]);
+          candidates[i] = model.modify(candidates[i], updateQuery);
+          updatedDocs.push(candidates[i]);
         }
       }
     } catch (err) {
@@ -404,6 +407,7 @@ Datastore.prototype.update = function () {
 Datastore.prototype._remove = function (query, options, cb) {
   var callback
     , self = this
+    , candidates = this.getCandidates(query)
     , numRemoved = 0
     , multi
     , newData = []