IN ('db block gets',
　　'consistent gets') group by v$waitstat.class, v$waitstat.count
　　18。查看sga情况
　　SELECT NAME, BYTES FROM SYS.V_$SGASTAT ORDER BY NAME ASC
　　19。查看catched object
　　SELECT owner,              name,              db_link,              namespace,
　　type,              sharable_mem,              loads,              executions,
　　locks,              pins,              kept        FROM v$db_object_cache
　　20。查看V$SQLAREA
　　SELECT SQL_TEXT, SHARABLE_MEM, PERSISTENT_MEM, RUNTIME_MEM, SORTS,
　　VERSION_COUNT, LOADED_VERSIONS, OPEN_VERSIONS, USERS_OPENING, EXECUTIONS,
　　USERS_EXECUTING, LOADS, FIRST_LOAD_TIME, INVALIDATIONS, PARSE_CALLS, DISK_READS,
　　BUFFER_GETS, ROWS_PROCESSED FROM V$SQLAREA
　　21。查看object分类数量
　　select decode (o.type#,1,'INDEX' , 2,'TABLE' , 3 , 'CLUSTER' , 4, 'VIEW' , 5 ,
　　'SYNONYM' , 6 , 'SEQUENCE' , 'OTHER' ) object_type , count(*) quantity from
　　sys.obj$ o where o.type# > 1 group by decode (o.type#,1,'INDEX' , 2,'TABLE' , 3
　　, 'CLUSTER' , 4, 'VIEW' , 5 , 'SYNONYM' , 6 , 'SEQUENCE' , 'OTHER' ) union select
　　'COLUMN' , count(*) from sys.col$ union select 'DB LINK' , count(*) from
　　22。按用户查看object种类
　　select u.name schema,   sum(decode(o.type#, 1, 1, NULL)) indexes,
　　sum(decode(o.type#, 2, 1, NULL)) tables,   sum(decode(o.type#, 3, 1, NULL))
　　clusters,   sum(decode(o.type#, 4, 1, NULL)) views,   sum(decode(o.type#, 5, 1,
　　NULL)) synonyms,   sum(decode(o.type#, 6, 1, NULL)) sequences,
　　sum(decode(o.type#, 1, NULL, 2, NULL, 3, NULL, 4, NULL, 5, NULL, 6, NULL, 1))
　　others   from sys.obj$ o, sys.user$ u   where o.type# >= 1 and    u.user# =
　　o.owner# and   u.name <> 'PUBLIC'   group by u.name    order by
　　sys.link$ union select 'CONSTRAINT' , count(*) from sys.con$
　　23。有关connection的相关信息
　　1）查看有哪些用户连接
　　select s.osuser os_user_name,    decode(sign(48 - command), 1, to_char(command),
　　'Action Code #' || to_char(command) ) action,     p.program oracle_process,
　　status session_status,    s.terminal terminal,    s.program program,
　　s.username user_name, &nbs
　　p;  s.fixed_