Magento grid default limit

In Magento grid When I use $this->setDefaultLimit(200); in grid.php it changes the selected value in pager to 200 but when a user changes it to some other value sa开发者_运维问答y 50 , even after refreshing/clearing cache it doesnt set pager value to default 200, it remains 50. Where it is stored and how can it be overridden.

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There is a method setSaveParametersInSession()

which allows you to disable storing variables in session

Look into Mage_Adminhtml_Block_Widget_Grid