PGA,sga命中sql查询

经常忘记，记录这里，以便备查：

PGA的内存命中：

SELECT name profile,cnt,decode( total, 0, 0, round( cnt * 100 / total)) percentage
FROM ( SELECT name, value cnt, ( SUM( value ) OVER()) total
FROM v$sysstat
WHERE name LIKE 'workarea exec%');

-- 数据缓冲区高速缓存
SELECT physical_reads, db_block_gets, consistent_gets, NAME,
100 * ( 1 - ( physical_reads / (consistent_gets + db_block_gets - physical_reads))) "Data Buffer Hit Ratio"
FROM v$buffer_pool_statistics;

-- 重做日至缓冲区
SELECT a.VALUE redo_entries, b.VALUE redo_buffer_allocation_retries,
ROUND ((1 - b.VALUE / a.VALUE) * 100, 4) log_buffer_ratio
FROM v$sysstat a, v$sysstat b
WHERE a.NAME = 'redo entries' AND b.NAME = 'redo buffer allocation retries';

-- 数据字典高速缓存
SELECT SUM (pinhits) / SUM (pins) * 100 "hit radio"
FROM v$librarycache;

-- 库高速缓存
SELECT TO_CHAR (ROUND ((1 - SUM (getmisses) / SUM (gets)) * 100, 1)) || '%' "Dictionary Cache Hit Ratio"
FROM v$rowcache;

-- 排序
SELECT a.VALUE disk_sort, b.VALUE memory_sort, ROUND ((1 - a.VALUE / (a.VALUE + b.VALUE)) * 100, 4) sort_ratio
FROM v$sysstat a, v$sysstat b
WHERE a.NAME = 'sorts (disk)' AND b.NAME = 'sorts (memory)';

--找出相关的sql根据系统pid
select se.username,se.machine,sq.cpu_time,sq.sql_text from
v$process p,v$session se,v$sqlarea sq
where p.addr=se.paddr and se.sql_hash_value=sq.hash_value and p.addr='&pid';

列出cpu_time top 10

select cpu_time,sql_text
from (select sql_text,cpu_time,
rank() over (order by cpu_time desc) exec_rank
from v$sql
)
where exec_rank <=10;

执行次数最多的top 10
select sql_text,executions
from (select sql_text,executions,
rank() over
(order by executions desc) exec_rank
from v$sql)
where exec_rank <=10;

 

今天看到个帖子，关于索引中是否包含ROWID，做个DUMP跟踪下看，以下为详细的跟踪记录：

SQL> create table test as select rownum a ,'c' c from dual connect by level<101;

Table created

SQL> create index u_test on test(a);

Index created

SQL> select extent_id,file_id,block_id from dba_extents where segment_name='U_TEST';

EXTENT_ID FILE_ID BLOCK_ID

---------- ---------- ----------

0 6 121

SQL> alter system dump datafile 6 block 121; --assm 自动段管理位图占3个块，跳3个块

System altered

SQL> alter system dump datafile 6 block 124;

System altered

 

以下部分跟踪记录：

row#0[8024] flag: ------, lock: 0, len=12

col 0; len 2; (2): c1 02 ----------------索引键值

col 1; len 6; (6): 01 80 00 74 00 00 -----------------------rowid

row#1[8012] flag: ------, lock: 0, len=12

col 0; len 2; (2): c1 03

col 1; len 6; (6): 01 80 00 74 00 01

row#2[8000] flag: ------, lock: 0, len=12

col 0; len 2; (2): c1 04

col 1; len 6; (6): 01 80 00 74 00 02

SQL> create unique index u_test on test(a);

Index created

SQL> select extent_id,file_id,block_id from dba_extents where segment_name='U_TEST';

EXTENT_ID FILE_ID BLOCK_ID

---------- ---------- ----------

0 6 121

SQL> alter system dump datafile 6 block 124;

以下部分跟踪记录：

row#0[8025] flag: ------, lock: 0, len=11, data:(6): 01 80 00 74 00 00

col 0; len 2; (2): c1 02

row#1[8014] flag: ------, lock: 0, len=11, data:(6): 01 80 00 74 00 01

col 0; len 2; (2): c1 03

row#2[8003] flag: ------, lock: 0, len=11, data:(6): 01 80 00 74 00 02

col 0; len 2; (2): c1 04

row#3[7992] flag: ------, lock: 0, len=11, data:(6): 01 80 00 74 00 03

 

如上所示：唯一索引不包含ROWID，普通索引包含rowid.

 

 

Oracle常用dump命令，记录一下备查。

一.Memory Dumps

1).Global Area

ALTER SESSION SET EVENTS 'immediate trace name global_area level n';

1 包含PGA
2 包含SGA
4 包含UGA
8 包含indrect memory

2).Library Cache

ALTER SESSION SET EVENTS 'immediate trace name library_cache level n';

1 library cache统计信息
2 包含hash table histogram
3 包含object handle
4 包含object结构（Heap 0）

3).Row Cache

ALTER SESSION SET EVENTS 'immediate trace name row_cache level n';

1 row cache统计信息
2 包含hash table histogram
8 包含object结构

4).Buffers

ALTER SESSION SET EVENTS 'immediate trace name buffers level n';

1 buffer header
2 level 1 + block header
3 level 2 + block contents
4 level 1 + hash chain
5 level 2 + hash chain
6 level 3 + hash chain
8 level 4 + users/waiters
9 level 5 + users/waiters
10 level 6 + users/waiters

5).Buffer

ALTER SESSION SET EVENTS 'immediate trace name buffer level n';

n为某个指定block的rdba，该命令可以转储某个block在buffer中的所有版本。

6).Heap

ALTER SESSION SET EVENTS 'immediate trace name heapdump level level';

1 PGA摘要
2 SGA摘要
4 UGA摘要
8 Current call(CGA)摘要
16 User call(CGA)摘要
32 Large call(LGA)摘要
1025 PGA内容
2050 SGA内容
4100 UGA内容
8200 Current call内容
16400 User call内容
32800 Large call内容

7).Sub Heap

Oracle 9.0.1版本之前

ALTER SESSION SET EVENTS 'immediate trace name heapdump_addr level n';

若n为subheap的地址，转储的是subheap的摘要信息
若n为subheap的地址+1，转储的则是subheap的内容

Oracle 9.2.0版本之后

ALTER SESSION SET EVENTS 'immediate trace name heapdump_addr level n, addr m';

其中m为subheap的地址

n为1转储subheap的摘要，n为2转储subheap的内容

8).Process State

ALTER SESSION SET EVENTS 'immediate trace name processstate level n';

9).System State

ALTER SESSION SET EVENTS 'immediate trace name systemstate level n';

10).Error State

ALTER SESSION SET EVENTS 'immediate trace name errorstack level n';

0 Error stack
1 level 0 + function call stack
2 level 1 + process state
3 level 2 + context area

11).Hang Analysis

ALTER SESSION SET EVENTS 'immediate trace name hanganalyze level n';

12).Work Area

ALTER SESSION SET EVENTS 'immediate trace name workareatab_dump level n';

1 SGA信息
2 Workarea Table摘要信息
3 Workarea Table详细信息

13).Latches

ALTER SESSION SET EVENTS 'immediate trace name latches level n';

1 latch信息
2 统计信息

14).Events

ALTER SESSION SET EVENTS 'immediate trace name events level n';

1 session
2 process
3 system

15).Locks

ALTER SESSION SET EVENTS 'immediate trace name locks level n';

16).Shared Server Process

ALTER SESSION SET EVENTS 'immediate trace name shared_server_state level n';

n取值为1~14

17).Background Messages

ALTER SESSION SET EVENTS 'immediate trace name bg_messages level n';

n为pid+1

二.File Dumps

1).Block

Oracle 7之前

ALTER SESSION SET EVENTS 'immediate trace name blockdump level n';

n为block的rdba

Oracle8以后

ALTER SYSTEM DUMP DATAFILE file# BLOCK block#;

ALTER SYSTEM DUMP DATAFILE file#
BLOCK MIN minimum_block#
BLOCK MAX maximum_block#;

2).Tree Dump

ALTER SESSION SET EVENTS 'immediate trace name treedump level n';

n为object_id

3).Undo Segment Header

ALTER SYSTEM DUMP UNDO_HEADER 'segment_name';

4).Undo for a Transaction

ALTER SYSTEM DUMP UNDO BLOCK 'segment_name' XID xidusn xidslot xidsqn;

5).File Header

ALTER SESSION SET EVENTS 'immediate trace name file_hdrs level n';

1 控制文件中的文件头信息
2 level 1 + 文件头信息
3 level 2 + 数据文件头信息
10 level 3

6).Control file

ALTER SESSION SET EVENTS 'immediate trace name controlf level n';

1 文件头信息
2 level 1 + 数据库信息 + 检查点信息
3 level 2 + 可重用节信息
10 level 3

7).Redo log Header

ALTER SESSION SET EVENTS 'immediate trace name redohdr level n';

1 控制文件中的redo log信息
2 level 1 + 文件头信息
3 level 2 + 日志文件头信息
10 level 3

8).Redo log

ALTER SYSTEM DUMP LOGFILE 'FileName';

ALTER SYSTEM DUMP LOGFILE 'FileName'
SCN MIN MinimumSCN
SCN MAX MaximumSCN
TIME MIN MinimumTime
TIME MAX MaximumTime
LAYER Layer
OPCODE Opcode
DBA MIN FileNumber . BlockNumber
DBA MAX FileNumber . BlockNumber
RBA MIN LogFileSequenceNumber . BlockNumber
RBA MAX LogFileSequenceNumber . BlockNumber;

其中time = (((((yyyy - 1988)) * 12 + mm - 1) * 31 + dd - 1) * 24 + hh) * 60 + mi) * 60 + ss;

9).Loghist

ALTER SESSION SET EVENTS 'immediate trace name loghist level n';

1 dump控制文件中最早和最迟的日志历史项
>1 dump 2^n个日志历史项

 

 

由于需要，需缩小一数据库的ＳＧＡ，并重新分配:

alter system set sga_max_size=500m scope=spfile;

alter system set sga_target=500m scope=spfile;

shutdown immediate;

startup;

alter system system set shared_poll_size=300m scope=both;

记录下．

 

 

　昨天在给应用系统做升级的时候，脚本老是执行到一半，就出现，已断开数据库连接，跟踪后发现，执行到中间回出现，ora-03113错误(通信通道的文件结束),接着就是ora-03114(失去oracle连接）．

１．怀疑脚本问题，语句有问题，仔细研究下，没问题．

２．网络问题．换台机器还是一样．

３．换了个库试下，还是一样．

４．查了下　失效对象，有一些失效对象，compile之，结果得以解决．

总结：　一些失效的对象也会引起ora-03113 ora-3114错误