oracle性能监控

1. 性能监控之监控SQL语句
2.  
3. 分析表
4. analyze TABLE tablename compute statistics FOR ALL indexes;
5. analyze TABLE tablename compute statistics FOR ALL indexed COLUMNS;
6. analyze TABLE tablename compute statistics FOR TABLE;
7.  
8. 监控事例的等待
9.  
10. SELECT event,sum(decode(wait_Time,0,0,1)) "Prev",
11. sum(decode(wait_Time,0,1,0)) "Curr",count(*) "Tot"
12. FROM v$session_Wait
13. GROUP BY event ORDER BY 4;
14.  
15. 查看碎片程度高的表
16.  
17. SELECT segment_name table_name , COUNT(*) extents
18. FROM dba_segments WHERE owner NOT IN (SYS, SYSTEM) GROUP BY segment_name
19. HAVING COUNT(*) = (SELECT MAX( COUNT(*) FROM dba_segments GROUP BY segment_name);
20.  
21. 表、索引的存储情况检查
22.  
23. SELECT segment_name,sum(bytes),count(*) ext_quan FROM dba_extents WHERE
24. tablespace_name=&tablespace_name AND segment_type=TABLE GROUP BY tablespace_name,segment_name;
25.  
26. SELECT segment_name,count(*) FROM dba_extents WHERE segment_type=INDEX AND owner=&owner
27. GROUP BY segment_name;
28.  
29. 找使用CPU多的用户session
30.  
31. 12是cpu used BY this session
32.  
33. SELECT a.sid,spid,STATUS,substr(a.program,1,40) prog,a.terminal,osuser,value/60/100 value
34. FROM v$session a,v$process b,v$sesstat c
35. WHERE c.statistic#=12 and c.sid=a.sid and a.paddr=b.addr order by value desc;
36.  
37. 监控表空间的 I/O 比例
38.  
39. SELECT df.tablespace_name name,df.file_name "file",f.phyrds pyr,
40. f.phyblkrd pbr,f.phywrts pyw, f.phyblkwrt pbw
41. FROM v$filestat f, dba_data_files df
42. WHERE f.file# = df.file_id
43. ORDER BY df.tablespace_name;
44.  
45.  
46. 回滚段的争用情况
47.  
48. SELECT name, waits, gets, waits/gets "Ratio"
49. FROM v$rollstat a, v$rollname b
50. WHERE a.usn = b.usn;
51.  
52. 在某个用户下找所有的索引
53.  
54. SELECT user_indexes.table_name, user_indexes.index_name,uniqueness, column_name
55. FROM user_ind_columns, user_indexes
56. WHERE user_ind_columns.index_name = user_indexes.index_name
57. AND user_ind_columns.table_name = user_indexes.table_name
58. ORDER BY user_indexes.table_type, user_indexes.table_name,
59. user_indexes.index_name, column_position;
60.  
61.  
62. 监控文件系统的 I/O 比例
63.  
64. SELECT substr(a.file#,1,2) "#", substr(a.name,1,30) "Name",
65. a.STATUS, a.bytes, b.phyrds, b.phywrts
66. FROM v$datafile a, v$filestat b
67. WHERE a.file# = b.file#;
68.  
69. 监控 SGA 中字典缓冲区的命中率
70.  
71. SELECT parameter, gets,Getmisses , getmisses/(gets+getmisses)*100 "miss ratio",
72. (1-(sum(getmisses)/ (sum(gets)+sum(getmisses))))*100 "Hit ratio"
73. FROM v$rowcache
74. WHERE gets+getmisses <>0
75. GROUP BY parameter, gets, getmisses;
76.  
77. 监控 SGA 中共享缓存区的命中率，应该小于1％
78.  
79. SELECT sum(pins) "Total Pins", sum(reloads) "Total Reloads",
80. sum(reloads)/sum(pins) *100 libcache
81. FROM v$librarycache;
82.  
83. SELECT sum(pinhits-reloads)/sum(pins) "hit radio",sum(reloads)/sum(pins) "reload percent"
84. FROM v$librarycache;
85.  
86. 监控 SGA 的命中率
87.  
88. SELECT a.value + b.value "logical_reads", c.value "phys_reads",
89. round(100 * ((a.value+b.value)-c.value) / (a.value+b.value)) "BUFFER HIT RATIO"
90. FROM v$sysstat a, v$sysstat b, v$sysstat c
91. WHERE a.statistic# = 38 and b.statistic# = 39
92. AND c.statistic# = 40;
93.  
94. 监控 SGA 中重做日志缓存区的命中率，应该小于1％
95.  
96. SELECT name, gets, misses, immediate_gets, immediate_misses,
97. Decode(gets,0,0,misses/gets*100) ratio1,
98. Decode(immediate_gets+immediate_misses,0,0,
99. immediate_misses/(immediate_gets+immediate_misses)*100) ratio2
100. FROM v$latch WHERE name IN (redo allocation, redo copy);
101.  
102. 显示所有数据库对象的类别和大小
103.  
104. SELECT count(name) num_instances ,type ,sum(source_size) source_size ,
105. sum(parsed_size) parsed_size ,sum(code_size) code_size ,sum(error_size) error_size,
106. sum(source_size) +sum(parsed_size) +sum(code_size) +sum(error_size) size_required
107. FROM dba_object_size
108. GROUP BY type ORDER BY 2;
109.  
110. 监控内存和硬盘的排序比率，最好使它小于 .10，增加 sort_area_size
111.  
112. SELECT name, value FROM v$sysstat WHERE name IN (sorts (memory), sorts (disk));
113.  
114.  
115. 监控当前数据库谁在运行什么SQL语句
116.  
117. SELECT osuser, username, sql_text FROM v$session a, v$sqltext b
118. WHERE a.sql_address =b.address ORDER BY address, piece;
119.  
120. 监控字典缓冲区
121.  
122. SELECT (SUM(PINS - RELOADS)) / SUM(PINS) "LIB CACHE" FROM V$LIBRARYCACHE;
123. SELECT (SUM(GETS - GETMISSES - USAGE - FIXED)) / SUM(GETS) "ROW CACHE" FROM V$ROWCACHE;
124. SELECT SUM(PINS) "EXECUTIONS", SUM(RELOADS) "CACHE MISSES WHILE EXECUTING" FROM V$LIBRARYCACHE;
125.  
126. 后者除以前者,此比率小于1％,接近0％为好。
127.  
128. SELECT SUM(GETS) "DICTIONARY GETS",SUM(GETMISSES) "DICTIONARY CACHE GET MISSES"
129. FROM V$ROWCACHE
130.  
131. 监控 MTS
132.  
133. SELECT busy/(busy+idle) "shared servers busy" FROM v$dispatcher;
134.  
135. 此值大于0.5时，参数需加大
136.  
137. SELECT sum(wait)/sum(totalq) "dispatcher waits" FROM v$queue WHERE type=dispatcher;
138. SELECT count(*) FROM v$dispatcher;
139. SELECT servers_highwater FROM v$mts;
140.  
141. servers_highwater接近mts_max_servers时，参数需加大
142.  
143. 碎片程度
144.  
145. SELECT tablespace_name,count(tablespace_name) FROM dba_free_space GROUP BY tablespace_name
146. HAVING count(tablespace_name)>10;
147.  
148. ALTER tablespace name coalesce;
149. ALTER TABLE name deallocate unused;
150.  
151. CREATE OR REPLACE VIEW ts_blocks_v AS
152. SELECT tablespace_name,block_id,bytes,blocks,free space segment_name FROM dba_free_space
153. union ALL
154. SELECT tablespace_name,block_id,bytes,blocks,segment_name FROM dba_extents;
155.  
156. SELECT * FROM ts_blocks_v;
157.  
158. SELECT tablespace_name,sum(bytes),max(bytes),count(block_id) FROM dba_free_space
159. GROUP BY tablespace_name;