--查詢最慢的sql
select * from (
select parsing_user_id,executions,sorts
command_type,disk_reads,sql_text from v$sqlarea order by disk_reads desc
)where rownum<10
--查詢對應session
select SE.SID,SE.SERIAL#,PR.SPID,
SE.USERNAME,SE.STATUS,SE.TERMINAL,
SE.PROGRAM,SE.MODULE,
SE.SQL_ADDRESS,ST.EVENT,
ST.P1TEXT,SI.PHYSICAL_READS,SI.BLOCK_CHANGES from v$session se,v$session_wait st,
v$sess_io si,v$process pr
where st.SID=se.SID and st.SID=si.SID
AND SE.PADDR=PR.ADDR
AND SE.SID>6
AND ST.WAIT_TIME=0
AND ST.EVENT NOT LIKE '%SQL%'
ORDER BY PHYSICAL_READS DESC;
SELECT sql_address FROM V$SESSION SS,V$SQLTEXT TT
WHERE SS.SQL_HASH_VALUE=TT.HASH_VALUE AND SID=439;
v$sqltext：存儲的是完整的SQL,SQL被分割
v$sqlarea：存儲的SQL 和一些相關的信息，比如累計的執行次數，邏輯讀，物理讀等統計信息（統計）
v$sql：內存共享SQL區域中已經解析的SQL語句。（即時）
根據sid查找完整sql語句：
select sql_text from v$sqltext a where a.hash_value = (select sql_hash_value from v$session b where b.sid = '&sid' )
order by piece asc
select a.CPU_TIME,--CPU時間 百萬分之一（微秒）
a.OPTIMIZER_MODE,--優化方式
a.EXECUTIONS,--執行次數
a.DISK_READS,--讀盤次數
a.SHARABLE_MEM,--占用shared pool的內存多少
a.BUFFER_GETS,--讀取緩沖區的次數
a.COMMAND_TYPE,--命令類型(3:select,2:insert;6:update;7delete;47:pl/sql程序單元)
a.SQL_TEXT,--Sql語句
a.SHARABLE_MEM,
a.PERSISTENT_MEM,
a.RUNTIME_MEM,
a.PARSE_CALLS,
a.DISK_READS,
a.DIRECT_WRITES,
a.CONCURRENCY_WAIT_TIME,
a.USER_IO_WAIT_TIME
from SYS.V_$SQLAREA a
WHERE PARSING_SCHEMA_NAME = 'CHEA_FILL'--表空間
order by a.CPU_TIME desc
引用：http://jenniferok.iteye.com/blog/700985
從V$SQLAREA中查詢最占用資源的查詢 select b.username username,a.disk_reads reads,
SQL_TEXT
VARCHAR2(1000)
First thousand characters of the SQL text for the current cursor
SQL_ID
VARCHAR2(13)
SQL identifier of the parent cursor in the library cache
SHARABLE_MEM
NUMBER
Amount of shared memory used by a cursor. If multiple child cursors exist, then the sum of all shared memory used by all child cursors.
PERSISTENT_MEM
NUMBER
Fixed amount of memory used for the lifetime of an open cursor. If multiple child cursors exist, the fixed sum of memory used for the lifetime of all the child cursors.
RUNTIME_MEM
NUMBER
Fixed amount of memory required during execution of a cursor. If multiple child cursors exist, the fixed sum of all memory required during execution of all the child cursors.
SORTS
NUMBER
Sum of the number of sorts that were done for all the child cursors
VERSION_COUNT
NUMBER
Number of child cursors that are present in the cache under this parent
LOADED_VERSIONS
NUMBER
Number of child cursors that are present in the cache and have their context heap (KGL heap 6) loaded
OPEN_VERSIONS
NUMBER
The number of child cursors that are currently open under this current parent
USERS_OPENING
NUMBER
Number of users that have any of the child cursors open
FETCHES
NUMBER
Number of fetches associated with the SQL statement
EXECUTIONS
NUMBER
Total number of executions, totalled over all the child cursors
END_OF_FETCH_COUNT
NUMBER
Number of times this cursor was fully executed since the cursor was brought into the library cache. The value of this statistic is not incremented when the cursor is partially executed, either because it failed during the execution or because only the first few rows produced by this cursor are fetched before the cursor is closed or re-executed. By definition, the value of theEND_OF_FETCH_COUNT column should be less or equal to the value of the EXECUTIONS column.
USERS_EXECUTING
NUMBER
Total number of users executing the statement over all child cursors
LOADS
NUMBER
Number of times the object was loaded or reloaded
FIRST_LOAD_TIME
VARCHAR2(19)
Timestamp of the parent creation time
INVALIDATIONS
NUMBER
Total number of invalidations over all the child cursors
PARSE_CALLS
NUMBER
Sum of all parse calls to all the child cursors under this parent
DISK_READS
NUMBER
Sum of the number of disk reads over all child cursors
DIRECT_WRITES
NUMBER
Sum of the number of direct writes over all child cursors
BUFFER_GETS
NUMBER
Sum of buffer gets over all child cursors
APPLICATION_WAIT_TIME
NUMBER
Application wait time
CONCURRENCY_WAIT_TIME
NUMBER
Concurrency wait time
CLUSTER_WAIT_TIME
NUMBER
Cluster wait time
USER_IO_WAIT_TIME
NUMBER
User I/O Wait Time
PLSQL_EXEC_TIME
NUMBER
PL/SQL execution time
JAVA_EXEC_TIME
NUMBER
Java execution time
ROWS_PROCESSED
NUMBER
Total number of rows processed on behalf of this SQL statement
COMMAND_TYPE
NUMBER
Oracle command type definition
OPTIMIZER_MODE
VARCHAR2(25)
Mode under which the SQL statement was executed
PARSING_USER_ID
NUMBER
User ID of the user that has parsed the very first cursor under this parent
PARSING_SCHEMA_ID
NUMBER
Schema ID that was used to parse this child cursor
KEPT_VERSIONS
NUMBER
Number of child cursors that have been marked to be kept using the DBMS_SHARED_POOL package
ADDRESS
RAW(4 | 8)
Address of the handle to the parent for this cursor
HASH_VALUE
NUMBER
Hash value of the parent statement in the library cache
OLD_HASH_VALUE
NUMBER
Old SQL hash value
MODULE
VARCHAR2(64)
Contains the name of the module that was executing at the time that the SQL statement was first parsed as set by calling DBMS_APPLICATION_INFO .SET_MODULE
MODULE_HASH
NUMBER
Hash value of the module that is named in the MODULEcolumn
ACTION
VARCHAR2(64)
Contains the name of the action that was executing at the time that the SQL statement was first parsed as set by calling DBMS_APPLICATION_INFO .SET_ACTION
ACTION_HASH
NUMBER
Hash value of the action that is named in the ACTIONcolumn
SERIALIZABLE_ABORTS
NUMBER
Number of times the transaction fails to serialize, producing ORA-08177 errors, totalled over all the child cursors
CPU_TIME
NUMBER
CPU time (in microseconds) used by this cursor for parsing/executing/fetching
ELAPSED_TIME
NUMBER
Elapsed time (in microseconds) used by this cursor for parsing/executing/fetching
IS_OBSOLETE
VARCHAR2(1)
Indicates whether the cursor has become obsolete (Y ) or not (N ). This can happen if the number of child cursors is too large.
CHILD_LATCH
NUMBER
Child latch number that is protecting the cursor
PROGRAM_ID
NUMBER
Program identifie
