docs - correct some effective_cache_size guc sample settings (#12686)
docs - correct some effective_cache_size guc sample settings (#12686)


50wu/gpdb,lisakowen/gpdb,xinzweb/gpdb,lisakowen/gpdb,lisakowen/gpdb,greenplum-db/gpdb,greenplum-db/gpdb,greenplum-db/gpdb,greenplum-db/gpdb,greenplum-db/gpdb,50wu/gpdb,lisakowen/gpdb,greenplum-db/gpdb,lisakowen/gpdb,xinzweb/gpdb,xinzweb/gpdb,xinzweb/gpdb,lisakowen/gpdb,lisakowen/gpdb,greenplum-db/gpdb,xinzweb/gpdb,50wu/gpdb,xinzweb/gpdb,50wu/gpdb,xinzweb/gpdb,50wu/gpdb,greenplum-db/gpdb,50wu/gpdb,50wu/gpdb,50wu/gpdb,xinzweb/gpdb,lisakowen/gpdb