I have a excel file which is 50 MB in size but removing the slicer from that takes so much time. What could be the reason? Pivot table is build from SQL Query.
how can i filter data on query side. if i do that i suppose that every time filter is selected, my query will be executed. if yes, then user of this file would not like me to do that. Also One more question: I have one file of 125MB and other file of 50MB, but both take almost same time to filter the data. What could be the reason behind it?
Hard to say without looking at entire set up what's causing your issue.
There are several ways to do this. You can set up PowerQuery (if 2013), and set up filter conditions within, then load the data to PowerPivot Data model.
Other method is to go to Connection->Properties and edit Command text with SQL statement to filter.
Alternately you can go into Edit Query and edit in MS Query. But I've had little success there myself.