code/Debug/Helper/Performance.php
public function getCategory($timerName)
    {
        $category = self::CORE_CATEGORY;

        if (strpos($timerName, 'mage::dispatch') === 0 || strpos($timerName, 'column.phtml') > 0) {
            $category = self::SECTION;
        } else if (strpos($timerName, 'Model_Resource') > 0) {
            $category = self::DB_CATEGORY;
        } else if (strpos($timerName, 'EAV') === 0 || strpos($timerName, '_LOAD_ATTRIBUTE_') === 0 || strpos($timerName, '__EAV_') === 0) {
            $category = self::EAV_CATEGORY;
        } else if (strpos($timerName, 'CORE::create_object_of') === 0) {
            $category = self::CORE_CATEGORY;
        } else if (strpos($timerName, 'OBSERVER') === 0 || strpos($timerName, 'DISPATCH EVENT') === 0) {
            $category = self::EVENT_CATEGORY;
        } else if (strpos($timerName, 'BLOCK') === 0) {
            $category = self::LAYOUT_CATEGORY;
        } else if (strpos($timerName, 'init_config') === 0) {
            $category = self::CONFIG_CATEGORY;
        } else if (strpos($timerName, 'layout/') === 0 || strpos($timerName, 'layout_') > 0) {
            $category = self::LAYOUT_CATEGORY;
        } else if (strpos($timerName, 'Mage_Core_Model_Design') === 0) {
            $category = self::LAYOUT_CATEGORY;
        } else if (strpos($timerName, '.phtml') > 0) {
            $category = self::LAYOUT_CATEGORY;
        }

        return $category;
    }
public function getCategory($timerName)
    {
        $category = self::CORE_CATEGORY;

        if (strpos($timerName, 'mage::dispatch') === 0 || strpos($timerName, 'column.phtml') > 0) {
            $category = self::SECTION;
        } else if (strpos($timerName, 'Model_Resource') > 0) {
            $category = self::DB_CATEGORY;
        } else if (strpos($timerName, 'EAV') === 0 || strpos($timerName, '_LOAD_ATTRIBUTE_') === 0 || strpos($timerName, '__EAV_') === 0) {
            $category = self::EAV_CATEGORY;
        } else if (strpos($timerName, 'CORE::create_object_of') === 0) {
            $category = self::CORE_CATEGORY;
        } else if (strpos($timerName, 'OBSERVER') === 0 || strpos($timerName, 'DISPATCH EVENT') === 0) {
            $category = self::EVENT_CATEGORY;
        } else if (strpos($timerName, 'BLOCK') === 0) {
            $category = self::LAYOUT_CATEGORY;
        } else if (strpos($timerName, 'init_config') === 0) {
            $category = self::CONFIG_CATEGORY;
        } else if (strpos($timerName, 'layout/') === 0 || strpos($timerName, 'layout_') > 0) {
            $category = self::LAYOUT_CATEGORY;
        } else if (strpos($timerName, 'Mage_Core_Model_Design') === 0) {
            $category = self::LAYOUT_CATEGORY;
        } else if (strpos($timerName, '.phtml') > 0) {
            $category = self::LAYOUT_CATEGORY;
        }

        return $category;
    }
Determines category based on timer name

@param $timerName
@return string