Add some discussion of sort ordering to indices.sgml, which curiously had never touched the subject before.
Add some discussion of sort ordering to indices.sgml, which curiously
had never touched the subject before.

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