oracle 系统表 查询
<P>数据字典dict总是属于Oracle用户sys的。 <BR> 1、用户: <BR> select username from dba_users; <BR> 改口令 <BR> alter user spgroup identified by spgtest; <BR> 2、表空间: <BR> select * from dba_data_files; <BR> select * from dba_tablespaces;//表空间 <BR><BR> select tablespace_name,sum(bytes), sum(blocks) <BR> from dba_free_space group by tablespace_name;//空闲表空间 <BR><BR> select * from dba_data_files <BR> where tablespace_name='RBS';//表空间对应的数据文件 <BR><BR> select * from dba_segments <BR> where tablespace_name='INDEXS'; <BR> 3、数据库对象: <BR> select * from dba_objects; <BR> CLUSTER、DATABASE LINK、FUNCTION、INDEX、LIBRARY、PACKAGE、PACKAGE BODY、 <BR> PROCEDURE、SEQUENCE、SYNONYM、TABLE、TRIGGER、TYPE、UNDEFINED、VIEW。 <BR> 4、表: <BR> select * from dba_tables; <BR> analyze my_table compute statistics;->dba_tables后6列 <BR> select extent_id,bytes from dba_extents <BR> where segment_name='CUSTOMERS' and segment_type='TABLE' <BR> order by extent_id;//表使用的extent的信息。segment_type='ROLLBACK'查看回滚段的空间分配信息 <BR> 列信息: <BR> select distinct table_name <BR> from user_tab_columns <BR> where column_name='SO_TYPE_ID'; <BR> 5、索引: <BR> select * from dba_indexes;//索引,包括主键索引 <BR> select * from dba_ind_columns;//索引列 <BR> select i.index_name,i.uniqueness,c.column_name <BR> from user_indexes i,user_ind_columns c <BR> where i.index_name=c.index_name <BR> and i.table_name ='ACC_NBR';//联接使用 <BR> 6、序列: <BR> select * from dba_sequences; <BR> 7、视图: <BR> select * from dba_views; <BR> select * from all_views; <BR> text 可用于查询视图生成的脚本 <BR> 8、聚簇: <BR> select * from dba_clusters; <BR> 9、快照: <BR> select * from dba_snapshots; <BR> 快照、分区应存在相应的表空间。 <BR> 10、同义词: <BR> select * from dba_synonyms <BR> where table_owner='SPGROUP'; <BR> //if owner is PUBLIC,then the synonyms is a public synonym. <BR> if owner is one of users,then the synonyms is a *** synonym. <BR> 11、数据库链: <BR> select * from dba_db_links; <BR> 在spbase下建数据库链 <BR> create database link dbl_spnew <BR> connect to spnew identified by spnew using 'jhhx'; <BR> insert into acc_nbr@dbl_spnew <BR> select * from acc_nbr where nxx_nbr='237' and line_nbr='8888'; <BR> 12、触发器: <BR> select * from dba_trigers; <BR> 存储过程,函数从dba_objects查找。 <BR> 其文本:select text from user_source where name='BOOK_SP_EXAMPLE'; <BR> 建立出错:select * from user_errors; <BR> oracle总是将存储过程,函数等软件放在SYSTEM表空间。 <BR> 13、约束: <BR> (1)约束是和表关联的,可在create table或alter table table_name add/drop/modify来建立、修改、删除约束。 <BR> 可以临时禁止约束,如: <BR> alter table book_example <BR> disable constraint book_example_1; <BR> alter table book_example <BR> enable constraint book_example_1; <BR> (2)主键和外键被称为表约束,而not null和unique之类的约束被称为列约束。通常将主键和外键作为单独的命名约束放在字段列表下面,而列约束可放在列定义的同一行,这样更具有可读性。 <BR> (3)列约束可从表定义看出,即describe;表约束即主键和外键,可从dba_constraints和dba_cons_columns 查。 <BR> select * from user_constraints <BR> where table_name='BOOK_EXAMPLE'; <BR> select owner,CONSTRAINT_NAME,TABLE_NAME <BR> from user_constraints <BR> where constraint_type='R' <BR> order by table_name; <BR> (4)定义约束可以无名(系统自动生成约束名)和自己定义约束名(特别是主键、外键) <BR> 如:create table book_example <BR> (identifier number not null); <BR> create table book_example <BR> (identifier number constranit book_example_1 not null); <BR> 14、回滚段: <BR> 在所有的修改结果存入磁盘前,回滚段中保持恢复该事务所需的全部信息,必须以数据库发生的事务来相应确定其大小(DML语句才可回滚,create,drop,truncate等DDL不能回滚)。 <BR> 回滚段数量=并发事务/4,但不能超过50;使每个回滚段大小足够处理一个完整的事务; <BR> create rollback segment r05 <BR> tablespace rbs; <BR> create rollback segment rbs_cvt <BR> tablespace rbs <BR> storage(initial 1M next 500k); <BR> 使回滚段在线 <BR> alter rollback segment r04 online; <BR> 用dba_extents,v$rollback_segs监测回滚段的大小和动态增长。 <BR> 回滚段的区间信息 <BR> select * from dba_extents <BR> where segment_type='ROLLBACK' and segment_name='RB1'; <BR> 回滚段的段信息,其中bytes显示目前回滚段的字节数 <BR> select * from dba_segments <BR> where segment_type='ROLLBACK' and segment_name='RB1'; <BR> 为事物指定回归段 <BR> set transaction use rollback segment rbs_cvt <BR> 针对bytes可以使用回滚段回缩。 <BR> alter rollback segment rbs_cvt shrink; <BR> select bytes,extents,max_extents from dba_segments <BR> where segment_type='ROLLBACK' and segment_name='RBS_CVT'; <BR> 回滚段的当前状态信息: <BR> select * from dba_rollback_segs <BR> where segment_name='RB1'; <BR> 比多回滚段状态status,回滚段所属实例instance_num <BR> 查优化值optimal <BR> select n.name,s.optsize <BR> from v$rollname n,v$rollstat s <BR> where n.usn=s.usn; <BR> 回滚段中的数据 <BR> set transaction use rollback segment rb1;/*回滚段名*/ <BR> select n.name,s.writes <BR> from v$rollname n,v$rollstat s <BR> where n.usn=s.usn; <BR> 当事务处理完毕,再次查询$rollstat,比较writes(回滚段条目字节数)差值,可确定事务的大小。 <BR> 查询回滚段中的事务 <BR> column rr heading 'RB Segment' format a18 <BR> column us heading 'Username' format a15 <BR> column os heading 'Os User' format a10 <BR> column te heading 'Terminal' format a10 <BR> select r.name rr,nvl(s.username,'no transaction') us,s.osuser os,s.terminal te <BR> from v$lock l,v$session s,v$rollname r <BR> where l.sid=s.sid(+) <BR> and trunc(l.id1/65536)=R.USN <BR> and l.type='TX' <BR> and l.lmode=6 <BR> order by r.name; <BR> 15、作业 <BR> 查询作业信息 <BR> select job,broken,next_date,interval,what from user_jobs; <BR> select job,broken,next_date,interval,what from dba_jobs; <BR> 查询正在运行的作业 <BR> select * from dba_jobs_running; <BR> 使用包exec dbms_job.submit(:v_num,'a;',sysdate,'sysdate + (10/(24*60*60))')加入作业。间隔10秒钟 <BR>exec dbms_job.submit(:v_num,'a;',sysdate,'sysdate + (11/(24*60))')加入作业。间隔11分钟使用包exec dbms_job.remove(21)删除21号作业。<BR></P>
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