Oracle
里常用命令
(各种对象的操作与设置命令)
第一章：日志管理
1.forcing log switches sql> alter system switch logfile;2.forcing checkpoints sql> alter system checkpoint; 3.adding online redo log groups sql> alter database add logfile [group 4] sql> ('/disk3/log4a.rdo','/disk4/log4b.rdo') size 1m; 4.adding online redo log members sql> alter database add logfile member sql> '/disk3/log1b.rdo' to group 1, sql> '/disk4/log2b.rdo' to group 2; 5.changes the name of the online redo logfile sql> alter database rename file 'c:/oracle/oradata/oradb/redo01.log' sql> to 'c:/oracle/oradata/redo01.log'; 6.drop online redo log groups sql> alter database drop logfile group 3; 7.drop online redo log members sql> alter database drop logfile member 'c:/oracle/oradata/redo01.log'; 8.clearing online redo log files sql> alter database clear [unarchived] logfile 'c:/oracle/log2a.rdo'; 9.using logminer analyzing redo logfiles a. in the init.ora specify utl_file_dir = ' ' b. sql> execute dbms_logmnr_d.build('oradb.ora','c:/oracle/oradb/log'); c. sql> execute dbms_logmnr_add_logfile('c:/oracle/oradata/oradb/redo01.log', sql> dbms_logmnr.new); d. sql> execute dbms_logmnr.add_logfile('c:/oracle/oradata/oradb/redo02.log', sql> dbms_logmnr.addfile); e. sql> execute dbms_logmnr.start_logmnr(dictfilename=>'c:/oracle/oradb/log/oradb.ora'); f. sql> select * from v$logmnr_contents(v$logmnr_dictionary,v$logmnr_parameters sql> v$logmnr_logs); g. sql> execute dbms_logmnr.end_logmnr;
第二章：表空间管理
1.create tablespaces sql> create tablespace tablespace_name datafile 'c:/oracle/oradata/file1.dbf' size 100m, sql> 'c:/oracle/oradata/file2.dbf' size 100m minimum extent 550k [logging/nologging] sql> default storage (initial 500k next 500k maxextents 500 pctinccease 0) sql> [online/offline] [permanent/temporary] [extent_management_clause] 2.locally managed tablespace sql> create tablespace user_data datafile 'c:/oracle/oradata/user_data01.dbf' sql> size 500m extent management local uniform size 10m; 3.temporary tablespace sql> create temporary tablespace temp tempfile 'c:/oracle/oradata/temp01.dbf' sql> size 500m extent management local uniform size 10m; 4.change the storage setting sql> alter tablespace app_data minimum extent 2m; sql> alter tablespace app_data default storage(initial 2m next 2m maxextents 999); 5.taking tablespace offline or online sql> alter tablespace app_data offline; sql> alter tablespace app_data online; 6.read_only tablespace sql> alter tablespace app_data read only|write; 7.droping tablespac
e sql> drop tablespace app_data including contents; 8.enableing automatic extension of data files sql> alter tablespace app_data add datafile 'c:/oracle/oradata/app_data01.dbf' size 200m sql> autoextend on next 10m maxsize 500m; 9.change the size fo data files manually sql> alter database datafile 'c:/oracle/oradata/app_data.dbf' resize 200m; 10.Moving data files: alter tablespace sql> alter tablespace app_data rename datafile 'c:/oracle/oradata/app_data.dbf' sql> to 'c:/oracle/app_data.dbf'; 11.moving data files:alter database sql> alter database rename file 'c:/oracle/oradata/app_data.dbf' sql> to 'c:/oracle/app_data.dbf';
第三章：表
1.create a table sql> create table table_name (column datatype,column datatype]....) sql> tablespace tablespace_name [pctfree integer] [pctused integer] sql> [initrans integer] [maxtrans integer] sql> storage(initial 200k next 200k pctincrease 0 maxextents 50) sql> [logging|nologging] [cache|nocache] 2.copy an existing table sql> create table table_name [logging|nologging] as subquery 3.create temporary table sql> create global temporary table xay_temp as select * from xay; on commit preserve rows/on commit delete rows 4.pctfree = (average row size - initial row size) *100 /average row size pctused = 100-pctfree- (average row size*100/available data space) 5.change storage and block utilization parameter sql> alter table table_name pctfree=30 pctused=50 storage(next 500k sql> minextents 2 maxextents 100); 6.manually allocating extents sql> alter table table_name allocate extent(size 500k datafile 'c:/oracle/data.dbf'); 7.move tablespace sql> alter table employee move tablespace users; 8.deallocate of unused space sql> alter table table_name deallocate unused [keep integer] 9.truncate a table sql> truncate table table_name; 10.drop a table sql> drop table table_name [cascade constraints]; 11.drop a column sql> alter table table_name drop column comments cascade constraints checkpoint 1000; alter table table_name drop columns continue; 12.mark a column as unused sql> alter table table_name set unused column comments cascade constraints; alter table table_name drop unused columns checkpoint 1000; alter table orders drop columns continue checkpoint 1000 data_dictionary : dba_unused_col_tabs
第四章：索引
1.creating function-based indexes sql> create index summit.item_quantity on summit.item(quantity-quantity_shipped); 2.create a B-tree index sql> create [unique] index index_name on table_name(column,.. asc/desc) tablespace sql> tablespace_name [pctfree integer] [initrans integer] [maxtrans integer] sql> [logging | nologging] [nosort] storage(initial 200k next 200k pctincrease 0 sql> maxextents 50); 3.pctfree(index)=(maximum number of rows-initial number of rows)*100/maximum number of rows 4.creating reverse key indexes sql> create unique index xay_id on xay(a) reverse pctfree 30 storage(initial 200k sql> next 200k pctincrease 0 maxextents 50) tablespace indx; 5.create bitmap index sql> create bitmap index xay_id on xay(a) pctfree 30 storage( initial 200k next 200k sql> pctincrease 0 maxextents 50) tablespace indx; 6.change storage parameter of index sql> alter index xay_id storage (next 400k maxextents 100); 7.allocating index space sql> alter index xay_id allocate extent(size 200k datafile 'c:/oracle/index.dbf'); 8.alter index xay_id deallocate unused;
第五章：约束
1.define constraints as immediate or deferred sql> alter session set constraint[s] = immediate/deferred/default; set constraint[s] constraint_name/all immediate/deferred; 2. sql> drop table table_name cascade constraints sql> drop tablespace tablespace_name including contents cascade constraints 3. define constraints while create a table sql> create table xay(id number(7) constraint xay_id primary key deferrable sql> using index storage(initial 100k next 100k) tablespace indx); primary key/unique/references table(column)/check 4.enable constraints sql> alter table xay enable novalidate constraint xay_id; 5.enable constraints sql> alter table xay enable validate constraint xay_id;
第六章：
LOAD
数据
1.loading data using direct_load insert sql> insert /*+append */ into emp nologging sql> select * from emp_old; 2.parallel direct-load insert sql> alter session enable parallel dml; sql> insert /*+parallel(emp,2) */ into emp nologging sql> select * from emp_old; 3.using sql*loader sql> sqlldr scott/tiger / sql> control = ulcase6.ctl / sql> log = ulcase6.log direct=true
第七章：
reorganizing data 1.using expoty $exp scott/tiger tables(dept,emp) file=c:/emp.dmp log=exp.log compress=n direct=y 2.using import $imp scott/tiger tables(dept,emp) file=emp.dmp log=imp.log ignore=y 3.transporting a tablespace sql>alter tablespace sales_ts read only; $exp sys/.. file=xay.dmp transport_tablespace=y tablespace=sales_ts triggers=n constraints=n $copy datafile $imp sys/.. file=xay.dmp transport_tablespace=y datafiles=(/disk1/sles01.dbf,/disk2 /sles02.dbf) sql> alter tablespace sales_ts read write; 4.checking transport set sql> DBMS_tts.transport_set_check(ts_list =>'sales_ts' ..,incl_constraints=>true);
在表
transport_set_violations
中查看
sql> dbms_tts.isselfcontained
为
true
是，
表示自包含
第八章：
managing password security and resources 1.controlling account lock and password sql> alter user juncky identified by oracle account unlock; 2.user_provided password function sql> function_name(userid in varchar2(30),password in varchar2(30), old_password in varchar2(30)) return boolean 3.create a profile : password setting sql> create profile grace_5 limit failed_login_attempts 3 sql> password_lock_time unlimited password_life_time 30 sql>password_reuse_time 30 password_verify_function verify_function sql> password_grace_time 5; 4.altering a profile sql> alter profile default failed_login_attempts 3 sql> password_life_time 60 password_grace_time 10; 5.drop a profile sql> drop profile grace_5 [cascade]; 6.create a profile : resource limit sql> create profile developer_prof limit sessions_per_user 2 sql> cpu_per_session 10000 idle_time 60 connect_time 480; 7. view => resource_cost : alter resource cost dba_Users,dba_profiles 8. enable resource limits sql> alter system set resource_limit=true;
第九章：
Managing users 1.create a user: database authentication sql> create user juncky identified by oracle default tablespace users sql> temporary tablespace temp quota 10m on data password expire sql> [account lock|unlock] [profile profilename|default]; 2.change user quota on tablespace sql> alter user juncky quota 0 on users; 3.drop a user sql> drop user juncky [cascade]; 4. monitor user view: dba_users , dba_ts_quotas
第十章：
managing privileges 1.system privileges: view => system_privilege_map ,dba_sys_privs,session_privs 2.grant system privilege sql> grant create session,create table to managers; sql> grant create session to scott with admin option; with admin option can grant or revoke privilege from any user or role; 3.sysdba and sysoper privileges: sysoper: startup,shutdown,alter database open|mount,alter database backup controlfile, alter tablespace begin/end backup,recover database alter database archivelog,restricted session sysdba: sysoper privileges with admin option,create database,recover database until 4.password file members: view:=> v$pwfile_users 5.O7_dictionary_accessibility =true restriction access to view or tables in other schema 6.revoke system privilege sql> revoke create table from karen; sql> revoke create session from scott; 7.grant object privilege sql> grant execute on dbms_pipe to public; sql> grant update(first_name,salary) on employee to karen with grant option; 8.display objectprivilege : view => dba_tab_privs, dba_col_privs 9.revoke object privilege sql> revoke execute on dbms_pipe from scott [cascade constraints]; 10.audit record view :=> sys.aud$ 11. protecting the audit trail sql> audit delete on sys.aud$ by access; 12.statement auditing sql> audit user; 13.privilege auditing sql> audit select any table by summit by access; 14.schema object auditing sql> audit lock on summit.employee by access whenever successful; 15.view audit option : view=> all_def_audit_opts,dba_stmt_audit_opts,dba_priv_audit_opts,dba_obj_audit_opts 16.view audit result: view=> dba_audit_trail,dba_audit_exists,dba_audit_object,dba_audit_session,dba_audit_statement
第十一章：
manager role 1.create roles sql> create role sales_clerk; sql> create role hr_clerk identified by bonus; sql> create role hr_manager identified externally; 2.modify role sql> alter role sales_clerk identified by commission; sql> alter role hr_clerk identified externally; sql> alter role hr_manager not identified; 3.assigning roles sql> grant sales_clerk to scott; sql> grant hr_clerk to hr_manager; sql> grant hr_manager to scott with admin option; 4.establish default role sql> alter user scott default role hr_clerk,sales_clerk; sql> alter user scott default role all; sql> alter user scott default role all except hr_clerk; sql> alter user scott default role none; 5.enable and disable roles sql> set role hr_clerk; sql> set role sales_clerk identified by commission; sql> set role all except sales_clerk; sql> set role none; 6.remove role from user sql> revoke sales_clerk from scott; sql> revoke hr_manager from public; 7.remove role sql> drop role hr_manager; 8.display role information view: =>dba_roles,dba_role_privs,role_role_privs,dba_sys_privs,role_sys_privs,role_tab_privs,session_roles
第十二章
: BACKUP and RECOVERY 1. v$sga,v$instance,v$process,v$bgprocess,v$database,v$datafile,v$sgastat 2. Rman need set dbwr_IO_slaves or backup_tape_IO_slaves and large_pool_size 3. Monitoring Parallel Rollback > v$fast_start_servers , v$fast_start_transactions 4.perform a closed database backup (noarchivelog) > shutdown immediate > cp files /backup/ > startup 5.restore to a different location > connect system/manager as sysdba > startup mount > alter database rename file '/disk1/../user.dbf' to '/disk2/../user.dbf'; > alter database open; 6.recover syntax --recover a mounted database >recover database; >recover datafile '/disk1/data/df2.dbf'; >alter database
recover database; --recover an opened database >recover tablespace user_data; >recover datafile 2; >alter database recover datafile 2; 7.how to apply redo log files automatically >set autorecovery on >recover automatic datafile 4; 8.complete recovery: --method 1(mounted databae) >copy c:/backup/user.dbf c:/oradata/user.dbf >startup mount >recover datafile 'c:/oradata/user.dbf; >alter database open; --method 2(opened database,initially opened,not system or rollback datafile) >copy c:/backup/user.dbf c:/oradata/user.dbf (alter tablespace offline) >recover datafile 'c:/oradata/user.dbf' or >recover tablespace user_data; >alter database datafile 'c:/oradata/user.dbf' online or >alter tablespace user_data online; --method 3(opened database,initially closed not system or rollback datafile) >startup mount >alter database datafile 'c:/oradata/user.dbf' offline; >alter database open >copy c:/backup/user.dbf d:/oradata/user.dbf >alter database rename file 'c:/oradata/user.dbf' to 'd:/oradata/user.dbf' >recover datafile 'e:/oradata/user.dbf' or recover tablespace user_data; >alter tablespace user_data online; --method 4(loss of data file with no backup and have all archive log) >alter tablespace user_data offline immediate; >alter database create datafile 'd:/oradata/user.dbf' as 'c:/oradata/user.dbf'' >recover tablespace user_data; >alter tablespace user_data online 5.perform an open database backup > alter tablespace user_data begin backup; > copy files /backup/ > alter database datafile '/c:/../data.dbf' end backup; > alter system switch logfile; 6.backup a control file > alter database backup controlfile to 'control1.bkp'; > alter database backup controlfile to trace; 7.recovery (noarchivelog mode) > shutdown abort > cp files > startup 8.recovery of file in backup mode >alter database datafile 2 end backup; 9.clearing redo log file >alter database clear unarchived logfile group 1; >alter database clear unarchived logfile group 1 unrecoverable datafile; 10.redo log recovery >alter database add logfile group 3 'c:/oradata/redo03.log' size 1000k; >alter database drop logfile group 1; >alter database open; or >cp c:/oradata/redo02.log' c:/oradata/redo01.log >alter database clear logfile 'c:/oradata/log01.log';
1. 删除表的注意事项
在删除一个表中的全部数据时，须使用TRUNCATE TABLE 表名;因为用DROP TABLE，DELETE * FROM 表名时，TABLESPACE表空间该表的占用空间并未释放，反复几次DROP，DELETE操作后，该TABLESPACE上百兆的空间就被耗光了。
2.having 子句的用法
having 子句对 group by 子句所确定的行组进行控制,having 子句条件中只允许涉及常量,聚组函数或group by 子句中的列.
3.外部联接"+"的用法
外部联接"+"按其在"="的左边或右边分左联接和右联接.若不带"+"运算符的表中的一个行不直接匹配于带"+"预算符的表中的任何行,则前者的行与后者中的一个空行相匹配并被返回.若二者均不带’+’,则二者中无法匹配的均被返回.利用外部联接"+",可以替代效率十分低下的 not in 运算,大大提高运行速度.例如,下面这条命令执行起来很慢
用外联接提高表连接的查询速度
在作表连接(常用于视图)时，常使用以下方法来查询数据:
SELECT PAY_NO, PROJECT_NAME
FROM A
WHERE A.PAY_NO NOT IN (SELECT PAY_
NO FROM B WHERE VALUE >=120000);
---- 但是若表A有10000条记录，表B有10000条记录，则要用掉30分钟才能查完，主要因为NOT IN要进行一条一条的比较，共需要10000*10000次比较后，才能得到结果。该用外联接后，可以缩短到1分左右的时间:
SELECT PAY_NO,PROJECT_NAME
FROM A,B
WHERE A.PAY_NO=B.PAY_NO(+)
AND B.PAY_NO IS NULL
AND B.VALUE >=12000;
4.set transaction 命令的用法
在执行大事务时,有时oracle会报出如下的错误:
ORA-01555:snapshot too old (rollback segment too small)
这说明oracle给此事务随机分配的回滚段太小了,这时可以为它指定一个足够大的回滚段,以确保这个事务的成功执行.例如
set transaction use rollback segment roll_abc;
delete from table_name where ...
commit;
回滚段roll_abc被指定给这个delete事务,commit命令则在事务结束之后取消了回滚段的指定.
5.数据库重建应注意的问?
在利用import进行数据库重建过程中,有些视图可能会带来问题,因为结构输入的顺序可能造成视图的输入先于它低层次表的输入,这样建立视图就会失败.要解决这一问题,可采取分两步走的方法:首先输入结构,然后输入数据.命令举例如下 (uesrname:jfcl,password:hfjf,host sting:ora1,数据文件:expdata.dmp):
imp jfcl/hfjf@ora1 file=empdata.dmp rows=N
imp jfcl/hfjf@ora1 file=empdata.dmp full=Y buffer=64000
commit=Y ignore=Y
第一条命令输入所有数据库结构,但无记录.第二次输入结构和数据,64000字节提交一次.ignore=Y选项保证第二次输入既使对象存在的情况下也能成功.
select a.empno from emp a where a.empno not in
(select empno from emp1 where job=’SALE’);
倘若利用外部联接,改写命令如下:
select a.empno from emp a ,emp1 b
where a.empno=b.empno(+)
and b.empno is null
and b.job=’SALE’;
可以发现,运行速度明显提高.
6.从已知表新建另一个表：
CREATE TABLE b
AS SELECT * (可以是表a中的几列)
FROM a
WHERE a.column = ...;
7.查找、删除重复记录:
法一: 用Group by语句 此查找很快的
select count(num), max(name) from student --查找表中num列重复的，列出重复的记录数，并列出他的name属性
group by num
having count(num) >1 --按num分组后找出表中num列重复，即出现次数大于一次
delete from student(上面Select的)
这样的话就把所有重复的都删除了。-----慎重
法二:当表比较大(例如10万条以上)时,这个方法的效率之差令人无法忍受,需要另想办法:
---- 执行下面SQL语句后就可以显示所有DRAWING和DSNO相同且重复的记录
SELECT * FROM EM5_PIPE_PREFAB
WHERE ROWID!=(SELECT MAX(ROWID) FROM EM5_PIPE_PREFAB D --D相当于First,Second
WHERE EM5_PIPE_PREFAB.DRAWING=D.DRAWING AND
EM5_PIPE_PREFAB.DSNO=D.DSNO);
---- 执行下面SQL语句后就可以刪除所有DRAWING和DSNO相同且重复的记录
DELETE FROM EM5_PIPE_PREFAB
WHERE ROWID!=(SELECT MAX(ROWID) FROM EM5_PIPE_PREFAB D
WHERE EM5_PIPE_PREFAB.DRAWING=D.DRAWING AND
EM5_PIPE_PREFAB.DSNO=D.DSNO);
8.返回表中[N，M]条记录：
取得某列中第N大的行
select column_name from
(select table_name.*,dense_rank() over (order by column desc) rank from table_name)
where rank = &N；
假如要返回前5条记录：
select * from tablename where rownum<6;(或是rownum <= 5 或是rownum != 6)
假如要返回第5-9条记录：
select * from tablename
where …
and rownum<10
minus
select * from tablename
where …
and rownum<５
order by name
选出结果后用name排序显示结果。(先选再排序)
注意：只能用以上符号(<、<=、!=)。
select * from tablename where rownum != 10;返回的是前９条记录。
不能用：>,>=,=,Between...and。由于rownum是一个总是从1开始的伪列，Oracle 认为这种条件 不成立，查不到记录.
另外，这个方法更快：
select * from (
select rownum r,a from yourtable
where rownum <= 20
order by name )
where r > 10
这样取出第11-20条记录!(先选再排序再选)
要先排序再选则须用select嵌套：内层排序外层选。
rownum是随着结果集生成的，一旦生成，就不会变化了；同时,生成的结果是依次递加的，没有1就永远不会有2!
rownum 是在 查询集合产生的过程中产生的伪列，并且如果where条件中存在 rownum 条件的话，则:
1： 假如 判定条件是常量，则：
只能 rownum = 1, <= 大于1 的自然数， = 大于1 的数是没有结果的， 大于一个数也是没有结果的
即 当出现一个 rownum 不满足条件的时候则 查询结束 this is stop key!
2: 当判定值不是常量的时候
若条件是 = var , 则只有当 var 为1 的时候才满足条件，这个时候不存在 stop key ,必须进行 full scan ,对每个满足其他where条件的数据进行判定
选出一行后才能去选rownum=2的行……
9.快速编译所有视图
---- 当在把数据库倒入到新的服务器上后(数据库重建)，需要将视图重新编译一遍，因为该表空间视图到其它表空间的表的连接会出现问题，可以利用PL/SQL的语言特性，快速编译。
SQL >SPOOL ON.SQL
SQL >SELECT ‘ALTER VIEW ‘||TNAME||’
COMPILE;’ FROM TAB;
SQL >SPOOL OFF
然后执行ON.SQL即可。
SQL >@ON.SQL
当然，授权和创建同义词也可以快速进行，如：
SQL >SELECT ‘GRANT SELECT ON ’
||TNAME||’ TO USERNAME;’ FROM TAB;
SQL >SELECT ‘CREATE SYNONYM
‘||TNAME||’ FOR USERNAME.’||TNAME||’;’ FROM TAB;
