Clarify use of btree indexes for ILIKE and ~*.
Clarify use of btree indexes for ILIKE and ~*.

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