本篇文章给大家带来了关于Oracle的相关知识,其中主要整理了数据字典、数据字典视图及动态性能视图的相关问题,数据字典记录数据库最基本的信息,包括数据字典基本表和数据字典视图,下面一起来看一下,希望对大家有帮助。
推荐教程:《Oracle视频教程》
数据字典记录数据库最基本的信息,包括数据字典基本表和数据字典视图;数据字典基本表由 $ORACLE_HOME\RDBMS\ADMIN\sql.bsq创建
数据字典基本表,属于sys用户,存放在system表空间,用户不能手动去修改数据字典基本表;
为了简化对数据字典基本表的使用,oracle提供了数据字典视图,还为数据字典视图创建了公有同义词,方便用户使用,数据字典视图和同义词的创建通过catalog.sql
USER_类型的视图表示当前登录用户拥有的信息;
ALL_类型的视图表示当前登录用户有权限看到的信息;
DBA_类型的视图表示数据库管理员能够看到的信息
如:
对应了2个数据库对象,一个是数据字典视图,一个是同义词,而且是先基于数据字典表创建数据字典视图,然后为视图创建了一个同名的同义词
查询USER_TABLES对应的数据库对象:
select * from dba_objects d where d.OBJECT_NAME='USER_TABLES';
查询USER_TABLES对应的视图:
select * from dba_views d where d.view_name='USER_TABLES';
查询USER_TABLES对应视图的创建语句:
SQL> SET LONG 10000;SQL> select d.text from dba_views d where d.view_name='USER_TABLES';TEXT--------------------------------------------------------------------------------select o.name, decode(bitand(t.property,2151678048), 0, ts.name, decode(t.ts#, 0, null, ts.name)), decode(bitand(t.property, 1024), 0, null, co.name), decode((bitand(t.property, 512)+bitand(t.flags, 536870912)), 0, null, co.name), decode(bitand(t.trigflag, 1073741824), 1073741824, 'UNUSABLE', 'VALID'), decode(bitand(t.property, 32+64), 0, mod(t.pctfree$, 100), 64, 0, null), decode(bitand(ts.flags, 32), 32, to_number(NULL), decode(bitand(t.property, 32+64), 0, t.pctused$, 64, 0, null)), decode(bitand(t.property, 32), 0, t.initrans, null), decode(bitand(t.property, 32), 0, t.maxtrans, null), decode(bitand(t.property, 17179869184), 17179869184, ds.initial_stg * ts.blocksize, s.iniexts * ts.blocksize), decode(bitand(t.property, 17179869184), 17179869184, ds.next_stg * ts.blocksize, s.extsize * ts.blocksize), decode(bitand(t.property, 17179869184), 17179869184, ds.minext_stg, s.minexts), decode(bitand(t.property, 17179869184), 17179869184, ds.maxext_stg, s.maxexts), decode(bitand(ts.flags, 3), 1, to_number(NULL), decode(bitand(t.property, 17179869184), 17179869184, ds.pctinc_stg, s.extpct)), decode(bitand(ts.flags, 32), 32, to_number(NULL), decode(bitand(o.flags, 2), 2, 1, decode(bitand(t.property, 17179869184), 17179869184, ds.frlins_stg, decode(s.lists, 0, 1, s.lists)))), decode(bitand(ts.flags, 32), 32, to_number(NULL), decode(bitand(o.flags, 2), 2, 1, decode(bitand(t.property, 17179869184), 17179869184, ds.maxins_stg, decode(s.groups, 0, 1, s.groups)))), decode(bitand(t.property, 32+64), 0, decode(bitand(t.flags, 32), 0, 'YES', 'NO'), null), decode(bitand(t.flags,1), 0, 'Y', 1, 'N', '?'), t.rowcnt, decode(bitand(t.property, 64), 0, t.blkcnt, null), decode(bitand(t.property, 64), 0, t.empcnt, null), decode(bitand(t.property, 64), 0, t.avgspc, null), t.chncnt, t.avgrln, t.avgspc_flb, decode(bitand(t.property, 64), 0, t.flbcnt, null), lpad(decode(t.degree, 32767, 'DEFAULT', nvl(t.degree,1)),10), lpad(decode(t.instances, 32767, 'DEFAULT', nvl(t.instances,1)),10), lpad(decode(bitand(t.flags, 8), 8, 'Y', 'N'),5), decode(bitand(t.flags, 6), 0, 'ENABLED', 'DISABLED'), t.samplesize, t.analyzetime, decode(bitand(t.property, 32), 32, 'YES', 'NO'), decode(bitand(t.property, 64), 64, 'IOT', decode(bitand(t.property, 512), 512, 'IOT_OVERFLOW', decode(bitand(t.flags, 536870912), 536870912, 'IOT_MAPPING', null))), decode(bitand(o.flags, 2), 0, 'N', 2, 'Y', 'N'), decode(bitand(o.flags, 16), 0, 'N', 16, 'Y', 'N'), decode(bitand(t.property, 8192), 8192, 'YES', decode(bitand(t.property, 1), 0, 'NO', 'YES')), decode(bitand(o.flags, 2), 2, 'DEFAULT', decode(bitand(decode(bitand(t.property, 17179869184), 17179869184, ds.bfp_stg, s.cachehint), 3), 1, 'KEEP', 2, 'RECYCLE', 'DEFAULT')), decode(bitand(o.flags, 2), 2, 'DEFAULT', decode(bitand(decode(bitand(t.property, 17179869184), 17179869184, ds.bfp_stg, s.cachehint), 12)/4, 1, 'KEEP', 2, 'NONE', 'DEFAULT')), decode(bitand(o.flags, 2), 2, 'DEFAULT', decode(bitand(decode(bitand(t.property, 17179869184), 17179869184, ds.bfp_stg, s.cachehint), 48)/16, 1, 'KEEP', 2, 'NONE', 'DEFAULT')), decode(bitand(t.flags, 131072), 131072, 'ENABLED', 'DISABLED'), decode(bitand(t.flags, 512), 0, 'NO', 'YES'), decode(bitand(t.flags, 256), 0, 'NO', 'YES'), decode(bitand(o.flags, 2), 0, NULL, decode(bitand(t.property, 8388608), 8388608, 'SYS$SESSION', 'SYS$TRANSACTION')), decode(bitand(t.flags, 1024), 1024, 'ENABLED', 'DISABLED'), decode(bitand(o.flags, 2), 2, 'NO', decode(bitand(t.property, 2147483648), 2147483648, 'NO', decode(ksppcv.ksppstvl, 'TRUE', 'YES', 'NO'))), decode(bitand(t.property, 1024), 0, null, cu.name), decode(bitand(t.flags, 8388608), 8388608, 'ENABLED', 'DISABLED'), case when (bitand(t.property, 32) = 32) then null when (bitand(t.property, 17179869184) = 17179869184) then decode(bitand(ds.flags_stg, 4), 4, 'ENABLED', 'DISABLED') else decode(bitand(s.spare1, 2048), 2048, 'ENABLED', 'DISABLED') end, case when (bitand(t.property, 32) = 32) then null when (bitand(t.property, 17179869184) = 17179869184) then decode(bitand(ds.flags_stg, 4), 4, case when bitand(ds.cmpflag_stg, 3) = 1 then 'BASIC' when bitand(ds.cmpflag_stg, 3) = 2 then 'OLTP' else decode(ds.cmplvl_stg, 1, 'QUERY LOW', 2, 'QUERY HIGH', 3, 'ARCHIVE LOW', 'ARCHIVE HIGH') end, null) else decode(bitand(s.spare1, 2048), 0, null, case when bitand(s.spare1, 16777216) = 16777216 -- 0x1000000 then 'OLTP' when bitand(s.spare1, 100663296) = 33554432 -- 0x2000000 then 'QUERY LOW' when bitand(s.spare1, 100663296) = 67108864 -- 0x4000000 then 'QUERY HIGH' when bitand(s.spare1, 100663296) = 100663296 -- 0x2000000+0x4000000 then 'ARCHIVE LOW' when bitand(s.spare1, 134217728) = 134217728 -- 0x8000000 then 'ARCHIVE HIGH' else 'BASIC' end) end, decode(bitand(o.flags, 128), 128, 'YES', 'NO'), decode(bitand(t.trigflag, 2097152), 2097152, 'YES', 'NO'), decode(bitand(t.property, 17179869184), 17179869184, 'NO', decode(bitand(t.property, 32), 32, 'N/A', 'YES')), decode(bitand(t.property,16492674416640),2199023255552,'FORCE', 4398046511104,'MANUAL','DEFAULT')from sys.ts$ ts, sys.seg$ s, sys.obj$ co, sys.tab$ t, sys.obj$ o, sys.deferred_stg$ ds, sys.obj$ cx, sys.user$ cu, x$ksppcv ksppcv, x$ksppi ksppiwhere o.owner# = userenv('SCHEMAID') and o.obj# = t.obj# and bitand(t.property, 1) = 0 and bitand(o.flags, 128) = 0 and t.bobj# = co.obj# (+) and t.ts# = ts.ts# and t.file# = s.file# (+) and t.block# = s.block# (+) and t.ts# = s.ts# (+) and t.obj# = ds.obj# (+) and t.dataobj# = cx.obj# (+) and cx.owner# = cu.user# (+) and ksppi.indx = ksppcv.indx and ksppi.ksppinm = '_dml_monitoring_enabled'
查询同义词:
select * from dba_synonyms d where d.synonym_name='USER_TABLES'
查询当前登录用户拥有的表
存储数据库中每时每刻都在变化的信息,主要是数据库的活动状态信息。把存储在内存里的信息,和存储在控制文件里的信息,以视图的形式展现出来;
初始化参数文件中所有项的值
当前进程的信息
有关会话的信息
基于当前操作会话进行的系统统计
从控制文件中提取有关重做日志组的信息
有关实例重做日志组文件名及其位置的信息
当前进程已获得和正在请求的锁信息
数据库事务信息
记录所有动态性能视图的定义信息
推荐教程:《Oracle视频教程》
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