目录
- --查看硬解析比
- --查看表锁
- --监控事例的等待
- --回滚段的争用情况
- --查看前台正在发出的SQL语句
- --数据表占用空间大小情况
- --查看表空间碎片大小
- --查看表空间占用磁盘情况
- --查看session使用回滚段
- --查看SGA区剩余可用内存
- --监控表空间I/O比例
- --监控文件系统的I/O比例
- --在某个用户下找所有的索引:
- --表、索引的存储情况检查
- --监控SGA命中率
- --监控SGA中字典缓冲区的命中率
- --监控 SGA 中共享缓存区的命中率,应该小于1%
- select sum(pins) "Total Pins", sum(reloads) "Total Reloads", sum(reloads) / sum(pins) * 100 libcache from v$librarycache; --监控 SGA 中重做日志缓存区的命中率,应该小于1%
- --监控内存和硬盘的排序比率,最好使它小于 .10
- --监控字典缓冲区
- --显示所有数据库对象的类别和大小
- --监控当前数据库谁在运行什么SQL 语句
- --v$dispatcher
- --非系统用户建在SYSTEM表空间中的表
- --性能最差的SQL
- --读磁盘数超100次的sql
- --最频繁执行的sql
- --查询使用CPU多的用户session
- --当前每个会话使用的对象数
- --监控log_buffer的使用情况:(值最好小于1%,否则增加log_buffer 的大小)
- --查看运行过的SQL 语句:
- SELECT SQL_TEXT FROM V$SQL --客户端主机信息 SYS_CONTEXT sys_context函数调用userenv命名空间来获取相关信息
- --查看回滚段名称及大小
- --parse to excute ratio(数据库的SQL语句执行和分析的比例) 越大越好
- --Parse CPU to Parse Elapsed(指数据库用在分析的CPU的时间和分析完成CPU时间对比)
- --Non-Parse CPU(用在非分析的过程中CPU 的等待了其它的资源)
- --Rollback segment(等待rollback segment 的header 比率,比率越小越好)
--查看硬解析比
select (select value from v$sysstat where name ='parse count (hard)')/(select value from v$sysstat where name='parse count (total)') from dual; 值越小越好。 --将常量解析改为强制软解析
alter system set cursor_sharing=force scope=both;
--查看表锁
select * from sys.v_$sqlarea where disk_reads>100
--监控事例的等待
select event, sum(decode(wait_Time, 0, 0, 1)) "Prev", sum(decode(wait_Time, 0, 1, 0)) "Curr", count(*) "Tot" from v$session_Wait group by event order by 4
--回滚段的争用情况
select name, waits, gets, waits / gets "Ratio" from v$rollstat a, v$rollname b where a.usn = b.usn
--查看前台正在发出的SQL语句
select user_name, sql_text from v$open_cursor where sid in (select sid from (select sid, serial#, username, program from v$session where status = 'ACTIVE'))
--数据表占用空间大小情况
select segment_name, tablespace_name, bytes, blocks from user_segments where segment_type = 'TABLE' ORDER BY bytes DESC, blocks DESC
--查看表空间碎片大小
select tablespace_name, round(sqrt(max(blocks) / sum(blocks)) * (100 / sqrt(sqrt(count(blocks)))), 2) FSFI from dba_free_space group by tablespace_name order by 1
--查看碎片程度高的表
SELECT segment_name table_name, COUNT(*) extents FROM dba_segments WHERE owner NOT IN ('SYS', 'SYSTEM') GROUP BY segment_name HAVING COUNT(*) = (SELECT MAX(COUNT(*)) FROM dba_segments GROUP BY segment_name);
--查看表空间占用磁盘情况
select b.file_id 文件id, b.tablespace_name 表空间名, b.bytes / 1024 / 1024 总大小, (b.bytes - sum(nvl(a.bytes, 0))) / 1024 / 1024 已使用大小, sum(nvl(a.bytes, 0)) / 1024 / 1024 剩余空间, sum(nvl(a.bytes, 0)) / (b.bytes) * 100 剩余百分比 from dba_free_space a, dba_data_files b where a.file_id = b.file_id group by b.tablespace_name, b.file_id, b.bytes order by b.file_id;
--查看session使用回滚段
SELECT r.name 回滚段名, s.sid, s.serial#, s.username 用户名, t.status, t.cr_get, t.phy_io, t.used_ublk, t.noundo, substr(s.program, 1, 78) 操作程序 FROM sys.v_$session s, sys.v_$transaction t, sys.v_$rollname r WHERE t.addr = s.taddr and t.xidusn = r.usn ORDER BY t.cr_get, t.phy_io
--查看SGA区剩余可用内存
select name, sgasize / 1024 / 1024 "Allocated(M)", bytes / 1024/1024 "自由空间(M)", round(bytes / sgasize * 100, 2) "自由空间百分比(%)" from (select sum(bytes) sgasize from sys.v_$sgastat) s, sys.v_$sgastat f where f.name = 'free memory'
--监控表空间I/O比例
select df.tablespace_name name, df.file_name "file", f.phyrds pyr, f.phyblkrd pbr, f.phywrts pyw, f.phyblkwrt pbw from v$filestat f, dba_data_files df where f.file# = df.file_id order by df.tablespace_name;
--监控文件系统的I/O比例
select substr(a.file#, 1, 2) "#", substr(a.name, 1, 30) "name", a.status, a.bytes, b.phyrds, b.phywrts from v$datafile a, v$filestat b where a.file# = b.file#
--在某个用户下找所有的索引:
select user_indexes.table_name, user_indexes.index_name, uniqueness, column_name from user_ind_columns, user_indexes where user_ind_columns.index_name = user_indexes.index_name and user_ind_columns.table_name = user_indexes.table_name order by user_indexes.table_type, user_indexes.table_name, user_indexes.index_name, column_position;
--表、索引的存储情况检查
select segment_name, sum(bytes), count(*) ext_quan from dba_extents where tablespace_name = '&tablespace_name' and segment_type = 'TABLE' group by tablespace_name, segment_name;
select segment_name, count(*) from dba_extents where segment_type = 'INDEX' and owner = '&owner' group by segment_name;
--监控SGA命中率
select a.value + b.value "logical_reads", c.value "phys_reads", round(100 * ((a.value + b.value) - c.value) / (a.value + b.value)) "BUFFER HIT RATIO" from v$sysstat a, v$sysstat b, v$sysstat c where a.statistic# = 48 and b.statistic# = 51 and c.statistic# = 55;
--监控SGA中字典缓冲区的命中率
select parameter, gets, Getmisses, getmisses / (gets + getmisses) * 100 "miss ratio", (1 - (sum(getmisses) / (sum(gets) + sum(getmisses)))) * 100 "Hit ratio" from v$rowcache where gets + getmisses <> 0 group by parameter, gets, getmisses;
--监控 SGA 中共享缓存区的命中率,应该小于1%
select sum(pins) "Total Pins",
sum(reloads) "Total Reloads",
sum(reloads) / sum(pins) * 100 libcache
from v$librarycache;
--监控 SGA 中重做日志缓存区的命中率,应该小于1%
SELECT name, gets, misses, immediate_gets, immediate_misses, Decode(gets, 0, 0, misses / gets * 100) ratio1, Decode(immediate_gets + immediate_misses, 0, 0, immediate_misses / (immediate_gets + immediate_misses) * 100) ratio2 FROM v$latch WHERE name IN ('redo allocation', 'redo copy');
--监控内存和硬盘的排序比率,最好使它小于 .10
SELECT name, value FROM v$sysstat WHERE name IN ('sorts (memory)', 'sorts (disk)');
--监控字典缓冲区
SELECT SUM(GETS) "DICTIONARY GETS",SUM(GETMISSES) "DICTIONARY CACHE GET MISSES" FROM V$ROWCACHE
--显示所有数据库对象的类别和大小
select count(name) num_instances, type, sum(source_size) source_size, sum(parsed_size) parsed_size, sum(code_size) code_size, sum(error_size) error_size, sum(source_size) + sum(parsed_size) + sum(code_size) + sum(error_size) size_required from dba_object_size group by type order by 2;
--监控当前数据库谁在运行什么SQL 语句
SELECT osuser, username, sql_text from v$session a, v$sqltext b where a.sql_address = b.address order by address, piece;
--v$dispatcher
select busy/(busy+idle) "shared servers busy" from v$dispatcher; --此值大于0.5时,参数需加大 select sum(wait)/sum(totalq) "dispatcher waits" from v$queue where type='dispatcher'; select count(*) from v$dispatcher; select servers_highwater from V$SHARED_SERVER_MONITOR;--servers_highwater接近MAX_SHARED_SERVERS时,参数需加大
--非系统用户建在SYSTEM表空间中的表
SELECT owner, table_name FROM DBA_TABLES WHERE tablespace_name in ('SYSTEM', 'USER_DATA') AND owner NOT IN ('SYSTEM', 'SYS', 'OUTLN', 'ORDSYS', 'MDSYS', 'SCOTT', 'HOSTEAC')
--性能最差的SQL
SELECT * FROM ( SELECT PARSING_USER_ID EXECUTIONS,SORTS,COMMAND_TYPE,DISK_READS,sql_text FROM v$sqlarea ORDER BY disk_reads DESC) WHERE ROWNUM<100;
--读磁盘数超100次的sql
select * from sys.v_$sqlarea where disk_reads>100;
--最频繁执行的sql
select * from sys.v_$sqlarea where executions>100
--查询使用CPU多的用户session
select a.sid, spid, status, substr(a.program, 1, 40) prog, a.terminal, osuser, value / 60 / 100 value from v$session a, v$process b, v$sesstat c where c.statistic# = 12 and c.sid = a.sid and a.paddr = b.addr order by value desc
--当前每个会话使用的对象数
SELECT a.sid, s.terminal, s.program, count(a.sid) FROM V$ACCESS a, V$SESSION s WHERE a.owner <> 'SYS' AND s.sid = a.sid GROUP BY a.sid, s.terminal, s.program ORDER BY count(a.sid)
--监控log_buffer的使用情况:(值最好小于1%,否则增加log_buffer 的大小)
select rbar.name, rbar.value, re.name, re.value, (rbar.value * 100) / re.value || '%' "radio" from v$sysstat rbar, v$sysstat re where rbar.name = 'redo buffer allocation retries' and re.name = 'redo entries';
--查看运行过的SQL 语句:
SELECT SQL_TEXT FROM V$SQL
--客户端主机信息 SYS_CONTEXT sys_context函数调用userenv命名空间来获取相关信息
select SYS_CONTEXT('USERENV', 'TERMINAL') terminal, SYS_CONTEXT('USERENV', 'LANGUAGE') language, SYS_CONTEXT('USERENV', 'SESSIONID') sessionid, SYS_CONTEXT('USERENV', 'INSTANCE') instance, SYS_CONTEXT('USERENV', 'ENTRYID') entryid, SYS_CONTEXT('USERENV', 'ISDBA') isdba, SYS_CONTEXT('USERENV', 'NLS_TERRITORY') nls_territory, SYS_CONTEXT('USERENV', 'NLS_CURRENCY') nls_currency, SYS_CONTEXT('USERENV', 'NLS_CALENDAR') nls_calendar, SYS_CONTEXT('USERENV', 'NLS_DATE_FORMAT') nls_date_format, SYS_CONTEXT('USERENV', 'NLS_DATE_LANGUAGE') nls_date_language, SYS_CONTEXT('USERENV', 'NLS_SORT') nls_sort, SYS_CONTEXT('USERENV', 'CURRENT_USER') current_user, SYS_CONTEXT('USERENV', 'CURRENT_USERID') current_userid, SYS_CONTEXT('USERENV', 'SESSION_USER') session_user, SYS_CONTEXT('USERENV', 'SESSION_USERID') session_userid, SYS_CONTEXT('USERENV', 'PROXY_USER') proxy_user, SYS_CONTEXT('USERENV', 'PROXY_USERID') proxy_userid, SYS_CONTEXT('USERENV', 'DB_DOMAIN') db_domain, SYS_CONTEXT('USERENV', 'DB_NAME') db_name, SYS_CONTEXT('USERENV', 'HOST') host, SYS_CONTEXT('USERENV', 'OS_USER') os_user, SYS_CONTEXT('USERENV', 'EXTERNAL_NAME') external_name, SYS_CONTEXT('USERENV', 'IP_ADDRESS') ip_address, SYS_CONTEXT('USERENV', 'NETWORK_PROTOCOL') network_protocol, SYS_CONTEXT('USERENV', 'BG_JOB_ID') bg_job_id, SYS_CONTEXT('USERENV', 'FG_JOB_ID') fg_job_id, SYS_CONTEXT('USERENV', 'AUTHENTICATION_TYPE') authentication_type, SYS_CONTEXT('USERENV', 'AUTHENTICATION_DATA') authentication_data from dual;
--查看回滚段名称及大小
SELECT a.owner || '.' || a.segment_name roll_name, a.tablespace_name tablespace, TO_CHAR(a.initial_extent) || ' / ' || TO_CHAR(a.next_extent) in_extents, TO_CHAR(a.min_extents) || ' / ' || TO_CHAR(a.max_extents) m_extents, a.status status, b.bytes bytes, b.extents extents, d.shrinks shrinks, d.wraps wraps, d.optsize opt FROM dba_rollback_segs a, dba_segments b, v$rollname c, v$rollstat d WHERE a.segment_name = b.segment_name AND a.segment_name = c.name(+) AND c.usn = d.usn(+) ORDER BY a.segment_name;
--parse to excute ratio(数据库的SQL语句执行和分析的比例) 越大越好
select round((1 - a.VALUE / b.VALUE )* 100, 2) "parse to excute ratio" from v$sysstat a, v$sysstat b where a.STATISTIC#=331 and b.STATISTIC#=330;
--Parse CPU to Parse Elapsed(指数据库用在分析的CPU的时间和分析完成CPU时间对比)
select round((1 - a.VALUE / b.VALUE )* 100, 2) "Parse CPU to Parse Elapsed" from v$sysstat a, v$sysstat b where a.STATISTIC#=328 and b.STATISTIC#=329;
--Non-Parse CPU(用在非分析的过程中CPU 的等待了其它的资源)
select round((1 - a.VALUE / b.VALUE )* 100, 2) "Non-Parse CPU" from v$sysstat a, v$sysstat b where a.STATISTIC#=328 and b.STATISTIC#=12;
--Rollback segment(等待rollback segment 的header 比率,比率越小越好)
select waits,gets,round(waits/gets*100,2) from v$rollstat a,v$rollname b where a.USN=b.usn --表字段的注释说明 select * from user_col_comments 数据字典: select * from dict order by table_name; 锁及资源信息: select * from v$lock;不包括DDL锁 数据库字符集: select * from sys.props$ where name='NLS_CHARACTERSET'; inin.ora参数: select name,value from v$parameter order by name; SQL 共享池: select sql_text from v$sqlarea; 数据库: select * from v$database 控制文件: select * from V$controlfile; 重做日志文件信息: select * from V$logfile; 来自控制文件中的日志文件信息: select * from V$log; 来自控制文件中的数据文件信息: select * from V$datafile; NLS参数当前值: select * from V$nls_parameters; ORACLE 版本信息: select * from v$version; 描述后台进程: select * from v$bgprocess; 查看版本信息: select * from product_component_version;
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