Add debug_query_string global variable for pgmonitor and debugging use.
Add debug_query_string global variable for pgmonitor and debugging use.

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