Add a caveat pointing out that constraint exclusion doesn't work with constraints the planner is unable to disprove, hence simple btree-compatible conditions should be used.  We've seen people try to get cute with stuff like date_part(something) = something at least twice now.  Even if we wanted to try to teach predtest.c about the properties of date_part, most of the useful variants aren't immutable so nothing could be proved.
Add a caveat pointing out that constraint exclusion doesn't work with
constraints the planner is unable to disprove, hence simple btree-compatible
conditions should be used.  We've seen people try to get cute with stuff
like date_part(something) = something at least twice now.  Even if we
wanted to try to teach predtest.c about the properties of date_part,
most of the useful variants aren't immutable so nothing could be proved.

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