--- CHistory.orig.php   2014-02-19 02:30:01.139807850 +0000
+++ CHistory.php        2014-02-19 02:30:13.387814135 +0000
@@ -85,7 +85,8 @@
                        'preservekeys'                          => null,
                        'sortfield'                                     => '',
                        'sortorder'                                     => '',
-                       'limit'                                         => null
+                       'limit'                                         => null,
+                       'compressValues'             => null
                );
                $options = zbx_array_merge($defOptions, $options);

@@ -198,6 +199,12 @@
                if (zbx_ctype_digit($options['limit']) && $options['limit']) {
                        $sqlParts['limit'] = $options['limit'];
                }
+
+               // compress output
+               $compressOutput = false;
+               if (!is_null($options['compressValues'])) {
+                       $compressOutput = true;
+               }

                $itemids = array();

@@ -228,6 +235,7 @@
                $dbRes = DBselect($sql, $sqlLimit);
                $count = 0;
                $group = array();
+               $lastValues = array();
                while ($data = DBfetch($dbRes)) {
                        if ($options['countOutput']) {
                                $result = $data;
@@ -235,6 +243,12 @@
                        else {
                                $itemids[$data['itemid']] = $data['itemid'];

+                               if($compressOutput){
+                                       if(isset($lastValues[$data['itemid']]) && $lastValues[$data['itemid']] != $data['value']){
+                                               $count++;
+                                       }
+                               }
+
                                $result[$count] = array();

                                // hostids
@@ -254,8 +268,9 @@
                                        $result[$count]['triggers'][] = array('triggerid' => $data['triggerid']);
                                        unset($data['triggerid']);
                                }
+
                                $result[$count] += $data;
-
+
                                // grouping
                                if ($groupOutput) {
                                        $dataid = $data[$options['groupOutput']];
@@ -264,7 +279,15 @@
                                        }
                                        $group[$dataid][] = $result[$count];
                                }
-                               $count++;
+
+                               if($compressOutput){
+                                       if(isset($lastValues[$data['itemid']]) && $lastValues[$data['itemid']] != $data['value']){
+                                               $count++;
+                                       }
+                                       $lastValues[$data['itemid']] = $data['value'];
+                               } else {
+                                       $count++;
+                               }
                        }
                }