Short-circuit AllocSetReset if nothing has been palloc'd in the memory context since the previous AllocSetReset.  Original patch by Atsushi Ogawa, editorialized on a little bit by Tom Lane.
Short-circuit AllocSetReset if nothing has been palloc'd in the memory
context since the previous AllocSetReset.  Original patch by Atsushi Ogawa,
editorialized on a little bit by Tom Lane.

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