Fix tutorial for references problem, from rainer.tammer@spg.schulergroup.com
Fix tutorial for references problem, from rainer.tammer@spg.schulergroup.com

ahachete/gpdb,rubikloud/gpdb,Chibin/gpdb,Chibin/gpdb,greenplum-db/gpdb,rvs/gpdb,ahachete/gpdb,randomtask1155/gpdb,postmind-net/postgres-xl,edespino/gpdb,royc1/gpdb,tangp3/gpdb,kaknikhil/gpdb,pavanvd/postgres-xl,rvs/gpdb,yazun/postgres-xl,atris/gpdb,janebeckman/gpdb,kmjungersen/PostgresXL,rubikloud/gpdb,royc1/gpdb,randomtask1155/gpdb,lintzc/gpdb,rubikloud/gpdb,snaga/postgres-xl,lpetrov-pivotal/gpdb,lpetrov-pivotal/gpdb,Postgres-XL/Postgres-XL,tangp3/gpdb,50wu/gpdb,Chibin/gpdb,ahachete/gpdb,tpostgres-projects/tPostgres,ahachete/gpdb,randomtask1155/gpdb,jmcatamney/gpdb,zaksoup/gpdb,cjcjameson/gpdb,50wu/gpdb,kaknikhil/gpdb,chrishajas/gpdb,Postgres-XL/Postgres-XL,atris/gpdb,foyzur/gpdb,zaksoup/gpdb,lisakowen/gpdb,0x0FFF/gpdb,cjcjameson/gpdb,Quikling/gpdb,kaknikhil/gpdb,lintzc/gpdb,lpetrov-pivotal/gpdb,snaga/postgres-xl,lpetrov-pivotal/gpdb,lisakowen/gpdb,chrishajas/gpdb,jmcatamney/gpdb,xinzweb/gpdb,cjcjameson/gpdb,yuanzhao/gpdb,ashwinstar/gpdb,CraigHarris/gpdb,0x0FFF/gpdb,edespino/gpdb,Chibin/gpdb,rvs/gpdb,rubikloud/gpdb,foyzur/gpdb,techdragon/Postgres-XL,0x0FFF/gpdb,royc1/gpdb,kmjungersen/PostgresXL,tangp3/gpdb,arcivanov/postgres-xl,0x0FFF/gpdb,Quikling/gpdb,yuanzhao/gpdb,Chibin/gpdb,tangp3/gpdb,postmind-net/postgres-xl,xinzweb/gpdb,50wu/gpdb,techdragon/Postgres-XL,chrishajas/gpdb,rvs/gpdb,randomtask1155/gpdb,xinzweb/gpdb,Quikling/gpdb,tpostgres-projects/tPostgres,lpetrov-pivotal/gpdb,arcivanov/postgres-xl,yazun/postgres-xl,kaknikhil/gpdb,postmind-net/postgres-xl,arcivanov/postgres-xl,lisakowen/gpdb,chrishajas/gpdb,edespino/gpdb,greenplum-db/gpdb,rubikloud/gpdb,Chibin/gpdb,tpostgres-projects/tPostgres,foyzur/gpdb,greenplum-db/gpdb,Postgres-XL/Postgres-XL,foyzur/gpdb,tangp3/gpdb,zeroae/postgres-xl,ashwinstar/gpdb,CraigHarris/gpdb,yazun/postgres-xl,yuanzhao/gpdb,randomtask1155/gpdb,snaga/postgres-xl,pavanvd/postgres-xl,janebeckman/gpdb,adam8157/gpdb,Quikling/gpdb,lintzc/gpdb,ahachete/gpdb,rvs/gpdb,adam8157/gpdb,rubikloud/gpdb,greenplum-db/gpdb,kaknikhil/gpdb,tangp3/gpdb,kmjungersen/PostgresXL,ovr/postgres-xl,foyzur/gpdb,techdragon/Postgres-XL,xuegang/gpdb,lisakowen/gpdb,zaksoup/gpdb,cjcjameson/gpdb,kaknikhil/gpdb,edespino/gpdb,techdragon/Postgres-XL,tpostgres-projects/tPostgres,jmcatamney/gpdb,foyzur/gpdb,lpetrov-pivotal/gpdb,atris/gpdb,Chibin/gpdb,zaksoup/gpdb,jmcatamney/gpdb,lintzc/gpdb,ahachete/gpdb,pavanvd/postgres-xl,Quikling/gpdb,rvs/gpdb,zeroae/postgres-xl,edespino/gpdb,ovr/postgres-xl,chrishajas/gpdb,rvs/gpdb,randomtask1155/gpdb,Quikling/gpdb,cjcjameson/gpdb,arcivanov/postgres-xl,kaknikhil/gpdb,rvs/gpdb,ahachete/gpdb,xuegang/gpdb,rvs/gpdb,CraigHarris/gpdb,snaga/postgres-xl,CraigHarris/gpdb,pavanvd/postgres-xl,tpostgres-projects/tPostgres,CraigHarris/gpdb,arcivanov/postgres-xl,rubikloud/gpdb,lpetrov-pivotal/gpdb,lisakowen/gpdb,adam8157/gpdb,Quikling/gpdb,pavanvd/postgres-xl,Quikling/gpdb,CraigHarris/gpdb,janebeckman/gpdb,edespino/gpdb,cjcjameson/gpdb,adam8157/gpdb,xuegang/gpdb,postmind-net/postgres-xl,janebeckman/gpdb,janebeckman/gpdb,lisakowen/gpdb,xinzweb/gpdb,xuegang/gpdb,Postgres-XL/Postgres-XL,royc1/gpdb,0x0FFF/gpdb,kmjungersen/PostgresXL,ashwinstar/gpdb,atris/gpdb,zaksoup/gpdb,oberstet/postgres-xl,kmjungersen/PostgresXL,xuegang/gpdb,zeroae/postgres-xl,ovr/postgres-xl,janebeckman/gpdb,chrishajas/gpdb,xuegang/gpdb,royc1/gpdb,oberstet/postgres-xl,atris/gpdb,greenplum-db/gpdb,zeroae/postgres-xl,lisakowen/gpdb,snaga/postgres-xl,atris/gpdb,ovr/postgres-xl,techdragon/Postgres-XL,ashwinstar/gpdb,xuegang/gpdb,0x0FFF/gpdb,50wu/gpdb,lintzc/gpdb,lintzc/gpdb,atris/gpdb,randomtask1155/gpdb,edespino/gpdb,xinzweb/gpdb,Chibin/gpdb,cjcjameson/gpdb,foyzur/gpdb,edespino/gpdb,royc1/gpdb,randomtask1155/gpdb,atris/gpdb,Quikling/gpdb,edespino/gpdb,arcivanov/postgres-xl,jmcatamney/gpdb,kaknikhil/gpdb,adam8157/gpdb,yuanzhao/gpdb,greenplum-db/gpdb,0x0FFF/gpdb,adam8157/gpdb,50wu/gpdb,yuanzhao/gpdb,ashwinstar/gpdb,ashwinstar/gpdb,CraigHarris/gpdb,ashwinstar/gpdb,adam8157/gpdb,oberstet/postgres-xl,lintzc/gpdb,50wu/gpdb,foyzur/gpdb,yuanzhao/gpdb,xuegang/gpdb,royc1/gpdb,oberstet/postgres-xl,tangp3/gpdb,jmcatamney/gpdb,jmcatamney/gpdb,xinzweb/gpdb,lisakowen/gpdb,Quikling/gpdb,Postgres-XL/Postgres-XL,yuanzhao/gpdb,jmcatamney/gpdb,zaksoup/gpdb,50wu/gpdb,edespino/gpdb,zaksoup/gpdb,CraigHarris/gpdb,greenplum-db/gpdb,yuanzhao/gpdb,rubikloud/gpdb,tangp3/gpdb,0x0FFF/gpdb,janebeckman/gpdb,CraigHarris/gpdb,Chibin/gpdb,yuanzhao/gpdb,xuegang/gpdb,yuanzhao/gpdb,lintzc/gpdb,yazun/postgres-xl,royc1/gpdb,janebeckman/gpdb,lpetrov-pivotal/gpdb,cjcjameson/gpdb,50wu/gpdb,adam8157/gpdb,zaksoup/gpdb,yazun/postgres-xl,kaknikhil/gpdb,zeroae/postgres-xl,xinzweb/gpdb,greenplum-db/gpdb,janebeckman/gpdb,oberstet/postgres-xl,postmind-net/postgres-xl,ahachete/gpdb,rvs/gpdb,lintzc/gpdb,chrishajas/gpdb,chrishajas/gpdb,ashwinstar/gpdb,cjcjameson/gpdb,ovr/postgres-xl,xinzweb/gpdb,janebeckman/gpdb,Chibin/gpdb,cjcjameson/gpdb,kaknikhil/gpdb