ASTERIXDB-1168: use either primary key or generated id for decorrelation.Change-Id: Ib5e232f3ba99018cd1aedfa4f8bb2f98affa0f55Reviewed-on: https://asterix-gerrit.ics.uci.edu/696Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu>Reviewed-by: Jianfeng Jia <jianfeng.jia@gmail.com>Reviewed-by: Till Westmann <tillw@apache.org>