Change bitmap scan cost per page formula back to upstream
Change bitmap scan cost per page formula back to upstream

See discussion at: http://www.postgresql-archive.org/Bitmap-table-scan-cost-per-page-formula-td5997588.html

This reverts commit 982bcd4e4f6d406f865a1753604de4839108f756

50wu/gpdb,jmcatamney/gpdb,50wu/gpdb,lisakowen/gpdb,Chibin/gpdb,ashwinstar/gpdb,Chibin/gpdb,edespino/gpdb,adam8157/gpdb,xinzweb/gpdb,ashwinstar/gpdb,adam8157/gpdb,edespino/gpdb,xinzweb/gpdb,edespino/gpdb,jmcatamney/gpdb,greenplum-db/gpdb,Chibin/gpdb,xinzweb/gpdb,edespino/gpdb,50wu/gpdb,greenplum-db/gpdb,jmcatamney/gpdb,Chibin/gpdb,jmcatamney/gpdb,edespino/gpdb,Chibin/gpdb,ashwinstar/gpdb,greenplum-db/gpdb,Chibin/gpdb,edespino/gpdb,lisakowen/gpdb,xinzweb/gpdb,jmcatamney/gpdb,edespino/gpdb,greenplum-db/gpdb,adam8157/gpdb,ashwinstar/gpdb,adam8157/gpdb,ashwinstar/gpdb,lisakowen/gpdb,lisakowen/gpdb,50wu/gpdb,Chibin/gpdb,jmcatamney/gpdb,greenplum-db/gpdb,adam8157/gpdb,lisakowen/gpdb,adam8157/gpdb,edespino/gpdb,jmcatamney/gpdb,edespino/gpdb,ashwinstar/gpdb,Chibin/gpdb,50wu/gpdb,50wu/gpdb,jmcatamney/gpdb,lisakowen/gpdb,xinzweb/gpdb,greenplum-db/gpdb,greenplum-db/gpdb,Chibin/gpdb,50wu/gpdb,adam8157/gpdb,greenplum-db/gpdb,adam8157/gpdb,edespino/gpdb,lisakowen/gpdb,ashwinstar/gpdb,xinzweb/gpdb,lisakowen/gpdb,xinzweb/gpdb,xinzweb/gpdb,ashwinstar/gpdb,Chibin/gpdb,50wu/gpdb