Index: frontends/php/include/classes/class.cchart.php
===================================================================
--- frontends/php/include/classes/class.cchart.php	(revision 12359)
+++ frontends/php/include/classes/class.cchart.php	(working copy)
@@ -237,7 +237,12 @@
 			$calc_field = 'round('.$x.'*(mod('.zbx_dbcast_2bigint('clock').'+'.$z.','.$p.'))/('.$p.'),0)';  /* required for 'group by' support of Oracle */
 
 			$sql_arr = array();
+			
+// [ZBX-3249] for partitioned DB installs!
+			if(ZBX_HISTORY_DATA_UPKEEP > -1) $real_item['history'] = ZBX_HISTORY_DATA_UPKEEP;
+//---
 
+
 			if((($real_item['history']*86400) > (time()-($this->from_time+$this->period/2))) &&			// should pick data from history or trends
 				(($this->period / $this->sizeX) <= (ZBX_MAX_TREND_DIFF / ZBX_GRAPH_MAX_SKIP_CELL)))		// is reasonable to take data from history?
 			{
Index: frontends/php/include/classes/class.cpie.php
===================================================================
--- frontends/php/include/classes/class.cpie.php	(revision 12359)
+++ frontends/php/include/classes/class.cpie.php	(working copy)
@@ -180,6 +180,10 @@
 
 			$sql_arr = array();
 
+// [ZBX-3249] for partitioned DB installs!
+			if(ZBX_HISTORY_DATA_UPKEEP > -1) $real_item['history'] = ZBX_HISTORY_DATA_UPKEEP;
+//---
+
 			if((($real_item['history']*86400) > (time()-($from_time+$this->period/2))) &&				// should pick data from history or trends
 				(($this->period / $this->sizeX) <= (ZBX_MAX_TREND_DIFF / ZBX_GRAPH_MAX_SKIP_CELL)))		// is reasonable to take data from history?
 			{
Index: frontends/php/include/defines.inc.php
===================================================================
--- frontends/php/include/defines.inc.php	(revision 12359)
+++ frontends/php/include/defines.inc.php	(working copy)
@@ -52,6 +52,10 @@
 
 	define('ZBX_SCRIPT_TIMEOUT',			360); // in seconds
 	define('ZBX_SCRIPT_BYTES_LIMIT',		1073741824); // 1073741824 is 1MB in bytes
+	
+// this define made for partitioned DB installs!!
+	define('ZBX_HISTORY_DATA_UPKEEP',		-1); // in days; -1: disabled, 0: always use trends
+
 /* END OF USERS DEFINES */
 
 	define('ZBX_FONT_NAME',			'DejaVuSans');