Surajit Chaudhuri Vivek R. Narasayya Ravishankar Ramamurthy A pay-as-you-go framework for query execution feedback. 1141-1152 2008 1 PVLDB 1 http://www.vldb.org/pvldb/1/1453977.pdf db/journals/pvldb/pvldb1.html#ChaudhuriNR08