Support specifying PRIMARY KEY for the SERIAL type. Change DEFAULT NULL to send back a NULL pointer  rather than a string "NULL". This seems to work, where sending  the string led to type conversion problems (and probably the wrong  thing anyway).
Support specifying PRIMARY KEY for the SERIAL type.
Change DEFAULT NULL to send back a NULL pointer
 rather than a string "NULL". This seems to work, where sending
 the string led to type conversion problems (and probably the wrong
 thing anyway).

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