Use backticks instead of double quotes for delimited identifiers in SQL++. Change-Id: I2db58d68e8e28befa4105504c261b101fa0285af Reviewed-on: https://asterix-gerrit.ics.uci.edu/909 Reviewed-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu> Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu> Reviewed-by: Till Westmann <tillw@apache.org>