I have a insert query in which 5 views have been used by doing UNION. Backtracking to each view, data is populated into the view from another view (2 more views in back in similar way).
Individually run ,4 views takes sub seconds to run and 1 view is taking a long time.
That view (view<-view<-view<-view) Like this way,Data is populating into this view. Data in views are around 16M.
Any suggestions on how to reduce the the execution time for such query