1.2 DBA常用的表
1.2.1 dba_开头
dba_users数据库用户信息
dba_segments 表段信息
dba_extents 数据区信息
dba_objects 数据库对象信息
dba_tablespaces 数据库表空间信息
dba_data_files 数据文件设置信息
dba_temp_files 临时数据文件信息
dba_rollback_segs 回滚段信息
dba_ts_quotas 用户表空间配额信息
dba_free_space 数据库空闲空间信息
dba_profiles 数据库用户资源限制信息
dba_sys_privs 用户的系统权限信息
dba_tab_privs 用户具有的对象权限信息
dba_col_privs 用户具有的列对象权限信息
dba_role_privs 用户具有的角色信息
dba_audit_trail 审计跟踪记录信息
dba_stmt_audit_opts 审计设置信息
dba_audit_object 对象审计结果信息
dba_audit_session 会话审计结果信息
dba_indexes 用户模式的索引信息
1.2.2 user_开头
user_objects 用户对象信息
user_source 数据库用户的所有资源对象信息
user_segments 用户的表段信息
user_tables 用户的表对象信息
user_tab_columns 用户的表列信息
user_constraints 用户的对象约束信息
user_sys_privs 当前用户的系统权限信息
user_tab_privs 当前用户的对象权限信息
user_col_privs 当前用户的表列权限信息
user_role_privs 当前用户的角色权限信息
user_indexes 用户的索引信息
user_ind_columns 用户的索引对应的表列信息
user_cons_columns 用户的约束对应的表列信息
user_clusters 用户的所有簇信息
user_clu_columns 用户的簇所包含的内容信息
user_cluster_hash_expressions 散列簇的信息
1.2.3 v$开头
v$database 数据库信息
v$datafile 数据文件信息
v$controlfile 控制文件信息
v$logfile 重做日志信息
v$instance 数据库实例信息
v$log 日志组信息
v$loghist 日志历史信息
v$sga 数据库SGA信息
v$parameter 初始化参数信息
v$process 数据库服务器进程信息
v$bgprocess 数据库后台进程信息
v$controlfile_record_section 控制文件记载的各部分信息
v$thread 线程信息
v$datafile_header 数据文件头所记载的信息
v$archived_log 归档日志信息
v$archive_dest 归档日志的设置信息
v$logmnr_contents 归档日志分析的DML DDL结果信息
v$logmnr_dictionary 日志分析的字典文件信息
v$logmnr_logs 日志分析的日志列表信息
v$tablespace 表空间信息
v$tempfile 临时文件信息
v$filestat 数据文件的I/O统计信息
v$undostat Undo数据信息
v$rollname 在线回滚段信息
v$session 会话信息
v$transaction 事务信息
v$rollstat 回滚段统计信息
v$pwfile_users 特权用户信息
v$sqlarea 当前查询过的sql语句访问过的资源及相关的信息
v$sql 与v$sqlarea基本相同的相关信息
v$sysstat 数据库系统状态信息
1.2.4 all_开头
all_users 数据库所有用户的信息
all_objects 数据库所有的对象的信息
all_def_audit_opts 所有默认的审计设置信息
all_tables 所有的表对象信息
all_indexes 所有的数据库对象索引的信息
1.2.5 session_开头
session_roles 会话的角色信息
session_privs 会话的权限信息
1.2.6 index_开头
index_stats 索引的设置和存储信息
1.2.7 伪表
dual 系统伪列表信息
常用SQL查询：
1、查看表空间的名称及大小
select t.tablespace_name, round(sum(bytes/(1024*1024)),0) ts_size
from dba_tablespaces t, dba_data_files d
where t.tablespace_name = d.tablespace_name
group by t.tablespace_name;
2、查看表空间物理文件的名称及大小
select tablespace_name, file_id, file_name,
round(bytes/(1024*1024),0) total_space
from dba_data_files
order by tablespace_name;
3、查看回滚段名称及大小
select segment_name, tablespace_name, r.status,
(initial_extent/1024) InitialExtent,(next_extent/1024) NextExtent,
max_extents, v.curext CurExtent
From dba_rollback_segs r, v$rollstat v
Where r.segment_id = v.usn(+)
order by segment_name;
4、查看控制文件
select name from v$controlfile;
5、查看日志文件
select member from v$logfile;
6、查看表空间的使用情况
select sum(bytes)/(1024*1024) as free_space,tablespace_name
from dba_free_space
group by tablespace_name;
SELECT A.TABLESPACE_NAME,A.BYTES TOTAL,B.BYTES USED, C.BYTES FREE,
(B.BYTES*100)/A.BYTES "% USED",(C.BYTES*100)/A.BYTES "% FREE"
FROM SYS.SM$TS_AVAIL A,SYS.SM$TS_USED B,SYS.SM$TS_FREE C
WHERE A.TABLESPACE_NAME=B.TABLESPACE_NAME AND A.TABLESPACE_NAME=C.TABLESPACE_NAME;
7、查看数据库库对象
select owner, object_type, status, count(*) count# from all_objects group by owner, object_type, status;
8、查看数据库的版本
Select version FROM Product_component_version
Where SUBSTR(PRODUCT,1,6)='Oracle';
9、查看数据库的创建日期和归档方式
Select Created, Log_Mode, Log_Mode From V$Database;
10、捕捉运行很久的SQL
column username format a12
column opname format a16
column progress format a8
select username,sid,opname,
round(sofar*100 / totalwork,0) || '%' as progress,
time_remaining,sql_text
from v$session_longops , v$sql
where time_remaining <> 0
and sql_address = address
and sql_hash_value = hash_value
/
11。查看数据表的参数信息
SELECT partition_name, high_value, high_value_length, tablespace_name,
pct_free, pct_used, ini_trans, max_trans, initial_extent,
next_extent, min_extent, max_extent, pct_increase, FREELISTS,
freelist_groups, LOGGING, BUFFER_POOL, num_rows, blocks,
empty_blocks, avg_space, chain_cnt, avg_row_len, sample_size,
last_analyzed
FROM dba_tab_partitions
--WHERE table_name = :tname AND table_owner = :towner
ORDER BY partition_position
12.查看还没提交的事务
select * from v$locked_object;
select * from v$transaction;
13。查找object为哪些进程所用
select
p.spid,
s.sid,
s.serial# serial_num,
s.username user_name,
a.type object_type,
s.osuser os_user_name,
a.owner,
a.object object_name,
decode(sign(48 - command),
1,
to_char(command), 'Action Code #' || to_char(command) ) action,
p.program oracle_process,
s.terminal terminal,
s.program program,
s.status session_status
from v$session s, v$access a, v$process p
where s.paddr = p.addr and
s.type = 'USER' and
a.sid = s.sid and
a.object='SUBSCRIBER_ATTR'
order by s.username, s.osuser
14。回滚段查看
select rownum, sys.dba_rollback_segs.segment_name Name, v$rollstat.extents
Extents, v$rollstat.rssize Size_in_Bytes, v$rollstat.xacts XActs,
v$rollstat.gets Gets, v$rollstat.waits Waits, v$rollstat.writes Writes,
sys.dba_rollback_segs.status status from v$rollstat, sys.dba_rollback_segs,
v$rollname where v$rollname.name(+) = sys.dba_rollback_segs.segment_name and
v$rollstat.usn (+) = v$rollname.usn order by rownum
15。耗资源的进程（top session）
select s.schemaname schema_name, decode(sign(48 - command), 1,
to_char(command), 'Action Code #' || to_char(command) ) action, status
session_status, s.osuser os_user_name, s.sid, p.spid , s.serial# serial_num,
nvl(s.username, '[Oracle process]') user_name, s.terminal terminal,
s.program program, st.value criteria_value from v$sesstat st, v$session s , v$process p
where st.sid = s.sid and st.statistic# = to_number('38') and ('ALL' = 'ALL'
or s.status = 'ALL') and p.addr = s.paddr order by st.value desc, p.spid asc, s.username asc, s.osuser asc
16。查看锁（lock）情况
select /*+ RULE */ ls.osuser os_user_name, ls.username user_name,
decode(ls.type, 'RW', 'Row wait enqueue lock', 'TM', 'DML enqueue lock', 'TX',
'Transaction enqueue lock', 'UL', 'User supplied lock') lock_type,
o.object_name object, decode(ls.lmode, 1, null, 2, 'Row Share', 3,
'Row Exclusive', 4, 'Share', 5, 'Share Row Exclusive', 6, 'Exclusive', null)
lock_mode, o.owner, ls.sid, ls.serial# serial_num, ls.id1, ls.id2
from sys.dba_objects o, ( select s.osuser, s.username, l.type,
l.lmode, s.sid, s.serial#, l.id1, l.id2 from v$session s,
v$lock l where s.sid = l.sid ) ls where o.object_id = ls.id1 and o.owner
<> 'SYS' order by o.owner, o.object_name
17。查看等待（wait）情况
SELECT v$waitstat.class, v$waitstat.count count, SUM(v$sysstat.value) sum_value
FROM v$waitstat, v$sysstat WHERE v$sysstat.name IN ('db block gets',
'consistent gets') group by v$waitstat.class, v$waitstat.count
18。查看sga情况
SELECT NAME, BYTES FROM SYS.V_$SGASTAT ORDER BY NAME ASC
19。查看catched object
SELECT owner, name, db_link, namespace,
type, sharable_mem, loads, executions,
locks, pins, kept FROM v$db_object_cache
20。查看V$SQLAREA
SELECT SQL_TEXT, SHARABLE_MEM, PERSISTENT_MEM, RUNTIME_MEM, SORTS,
VERSION_COUNT, LOADED_VERSIONS, OPEN_VERSIONS, USERS_OPENING, EXECUTIONS,
USERS_EXECUTING, LOADS, FIRST_LOAD_TIME, INVALIDATIONS, PARSE_CALLS, DISK_READS,
BUFFER_GETS, ROWS_PROCESSED FROM V$SQLAREA
21。查看object分类数量
select decode (o.type#,1,'INDEX' , 2,'TABLE' , 3 , 'CLUSTER' , 4, 'VIEW' , 5 ,
'SYNONYM' , 6 , 'SEQUENCE' , 'OTHER' ) object_type , count(*) quantity from
sys.obj$ o where o.type# > 1 group by decode (o.type#,1,'INDEX' , 2,'TABLE' , 3
, 'CLUSTER' , 4, 'VIEW' , 5 , 'SYNONYM' , 6 , 'SEQUENCE' , 'OTHER' ) union select
'COLUMN' , count(*) from sys.col$ union select 'DB LINK' , count(*) from
22。按用户查看object种类
select u.name schema, sum(decode(o.type#, 1, 1, NULL)) indexes,
sum(decode(o.type#, 2, 1, NULL)) tables, sum(decode(o.type#, 3, 1, NULL))
clusters, sum(decode(o.type#, 4, 1, NULL)) views, sum(decode(o.type#, 5, 1,
NULL)) synonyms, sum(decode(o.type#, 6, 1, NULL)) sequences,
sum(decode(o.type#, 1, NULL, 2, NULL, 3, NULL, 4, NULL, 5, NULL, 6, NULL, 1))
others from sys.obj$ o, sys.user$ u where o.type# >= 1 and u.user# =
o.owner# and u.name <> 'PUBLIC' group by u.name order by
sys.link$ union select 'CONSTRAINT' , count(*) from sys.con$
23。有关connection的相关信息
1）查看有哪些用户连接
select s.osuser os_user_name, decode(sign(48 - command), 1, to_char(command),
'Action Code #' || to_char(command) ) action, p.program oracle_process,
status session_status, s.terminal terminal, s.program program,
s.username user_name, s.fixed_table_sequence activity_meter, '' query,
0 memory, 0 max_memory, 0 cpu_usage, s.sid, s.serial# serial_num
from v$session s, v$process p where s.paddr=p.addr and s.type = 'USER'
order by s.username, s.osuser
2）根据v.sid查看对应连接的资源占用等情况
select n.name,
v.value,
n.class,
n.statistic#
from v$statname n,
v$sesstat v
where v.sid = 71 and
v.statistic# = n.statistic#
order by n.class, n.statistic#
3）根据sid查看对应连接正在运行的sql
select /*+ PUSH_SUBQ */
command_type,
sql_text,
sharable_mem,
persistent_mem,
runtime_mem,
sorts,
version_count,
loaded_versions,
open_versions,
users_opening,
executions,
users_executing,
loads,
first_load_time,
invalidations,
parse_calls,
disk_reads,
buffer_gets,
rows_processed,
sysdate start_time,
sysdate finish_time,
'>' || address sql_address,
'N' status
from v$sqlarea
where address = (select sql_address from v$session where sid = 71)
24．查询表空间使用情况
select a.tablespace_name "表空间名称",
100-round((nvl(b.bytes_free,0)/a.bytes_alloc)*100,2) "占用率(%)",
round(a.bytes_alloc/1024/1024,2) "容量(M)",
round(nvl(b.bytes_free,0)/1024/1024,2) "空闲(M)",
round((a.bytes_alloc-nvl(b.bytes_free,0))/1024/1024,2) "使用(M)",
Largest "最大扩展段(M)",
to_char(sysdate,'yyyy-mm-dd hh24:mi:ss') "采样时间"
from (select f.tablespace_name,
sum(f.bytes) bytes_alloc,
sum(decode(f.autoextensible,'YES',f.maxbytes,'NO',f.bytes)) maxbytes
from dba_data_files f
group by tablespace_name) a,
(select f.tablespace_name,
sum(f.bytes) bytes_free
from dba_free_space f
group by tablespace_name) b,
(select round(max(ff.length)*16/1024,2) Largest,
ts.name tablespace_name
from sys.fet$ ff, sys.file$ tf,sys.ts$ ts
where ts.ts#=ff.ts# and ff.file#=tf.relfile# and ts.ts#=tf.ts#
group by ts.name, tf.blocks) c
where a.tablespace_name = b.tablespace_name and a.tablespace_name = c.tablespace_name
25. 查询表空间的碎片程度
select tablespace_name,count(tablespace_name) from dba_free_space group by tablespace_name
having count(tablespace_name)>10;
alter tablespace name coalesce;
alter table name deallocate unused;
create or replace view ts_blocks_v as
select tablespace_name,block_id,bytes,blocks,'free space' segment_name from dba_free_space
union all
select tablespace_name,block_id,bytes,blocks,segment_name from dba_extents;
select * from ts_blocks_v;
select tablespace_name,sum(bytes),max(bytes),count(block_id) from dba_free_space
group by tablespace_name;
26。查询有哪些数据库实例在运行
select inst_name from v$active_instances;
===========================================================
######### 创建数据库----look $ORACLE_HOME/rdbms/admin/buildall.sql #############
create database db01
maxlogfiles 10
maxdatafiles 1024
maxinstances 2
logfile
GROUP 1 ('/u01/oradata/db01/log_01_db01.rdo') SIZE 15M,
GROUP 2 ('/u01/oradata/db01/log_02_db01.rdo') SIZE 15M,
GROUP 3 ('/u01/oradata/db01/log_03_db01.rdo') SIZE 15M,
datafile 'u01/oradata/db01/system_01_db01.dbf') SIZE 100M,
undo tablespace UNDO
datafile '/u01/oradata/db01/undo_01_db01.dbf' SIZE 40M
default temporary tablespace TEMP
tempfile '/u01/oradata/db01/temp_01_db01.dbf' SIZE 20M
extent management local uniform size 128k
character set AL32UTE8
national character set AL16UTF16
set time_zone='America/New_York';
############### 数据字典 ##########
set wrap off
select * from v$dba_users;
grant select on table_name to user/rule;
select * from user_tables;
select * from all_tables;
select * from dba_tables;
revoke dba from user_name;
shutdown immediate
startup nomount
select * from v$instance;
select * from v$sga;
select * from v$tablespace;
alter session set nls_language=american;
alter database mount;
select * from v$database;
alter database open;
desc dictionary
select * from dict;
desc v$fixed_table;
select * from v$fixed_table;
set oracle_sid=foxconn
select * from dba_objects;
set serveroutput on
execute dbms_output.put_line('sfasd');
############# 控制文件 ###########
select * from v$database;
select * from v$tablespace;
select * from v$logfile;
select * from v$log;
select * from v$backup;
/*备份用户表空间*/
alter tablespace users begin backup;
select * from v$archived_log;
select * from v$controlfile;
alter system set control_files='$ORACLE_HOME/oradata/u01/ctrl01.ctl',
'$ORACLE_HOME/oradata/u01/ctrl02.ctl' scope=spfile;
cp $ORACLE_HOME/oradata/u01/ctrl01.ctl $ORACLE_HOME/oradata/u01/ctrl02.ctl
startup pfile='../initSID.ora'
select * from v$parameter where name like 'control%' ;
show parameter control;
select * from v$controlfile_record_section;
select * from v$tempfile;
/*备份控制文件*/
alter database backup controlfile to '../filepath/control.bak';
/*备份控制文件，并将二进制控制文件变为了asc 的文本文件*/
alter database backup controlfile to trace;
############### redo log ##############
archive log list;
alter system archive log start;--启动自动存档
alter system switch logfile;--强行进行一次日志switch
alter system checkpoint;--强制进行一次checkpoint
alter tablspace users begin backup;
alter tablespace offline;
/*checkpoint 同步频率参数FAST_START_MTTR_TARGET,同步频率越高，系统恢复所需时间越短*/
show parameter fast;
show parameter log_checkpoint;
/*加入一个日志组*/
alter database add logfile group 3 ('/$ORACLE_HOME/oracle/ora_log_file6.rdo' size 10M);
/*加入日志组的一个成员*/
alter database add logfile member '/$ORACLE_HOME/oracle/ora_log_file6.rdo' to group 3;
/*删除日志组:当前日志组不能删；活动的日志组不能删；非归档的日志组不能删*/
alter database drop logfile group 3;
/*删除日志组中的某个成员，但每个组的最后一个成员不能被删除*/
alter databse drop logfile member '$ORACLE_HOME/oracle/ora_log_file6.rdo';
/*清除在线日志*/
alter database clear logfile '$ORACLE_HOME/oracle/ora_log_file6.rdo';
alter database clear logfile group 3;
/*清除非归档日志*/
alter database clear unarchived logfile group 3;
/*重命名日志文件*/
alter database rename file '$ORACLE_HOME/oracle/ora_log_file6.rdo' to '$ORACLE_HOME/oracle/ora_log_file6a.rdo';
show parameter db_create;
alter system set db_create_online_log_dest_1='path_name';
select * from v$log;
select * from v$logfile;
/*数据库归档模式到非归档模式的互换,要启动到mount状态下才能改变;startup mount;然后再打开数据库.*/
alter database noarchivelog/archivelog;
achive log start;---启动自动归档
alter system archive all;－－手工归档所有日志文件
select * from v$archived_log;
show parameter log_archive;
###### 分析日志文件logmnr ##############
1) 在init.ora中set utl_file_dir 参数
2) 重新启动oracle
3) create 目录文件
desc dbms_logmnr_d;
dbms_logmnr_d.build;
4) 加入日志文件 add/remove log file
dhms_logmnr.add_logfile
dbms_logmnr.removefile
5) start logmnr
dbms_logmnr.start_logmnr
6) 分析出来的内容查询 v$logmnr_content --sqlredo/sqlundo
实践：
desc dbms_logmnr_d;
/*对数据表做一些操作，为恢复操作做准备*/
update 表 set qty=10 where stor_id=6380;
delete 表 where stor_id=7066;
/***********************************/
utl_file_dir的路径
execute dbms_logmnr_d.build('foxdict.ora','$ORACLE_HOME/oracle/admin/fox/cdump');
execute dbms_logmnr.add_logfile('$ORACLE_HOME/oracle/ora_log_file6.log',dbms_logmnr.newfile);
execute dbms_logmnr.start_logmnr(dictfilename=>'$ORACLE_HOME/oracle/admin/fox/cdump/foxdict.ora');
######### tablespace ##############
select * form v$tablespace;
select * from v$datafile;
/*表空间和数据文件的对应关系*/
select t1.name,t2.name from v$tablespace t1,v$datafile t2 where t1.ts#=t2.ts#;
alter tablespace users add datafile 'path' size 10M;
select * from dba_rollback_segs;
/*限制用户在某表空间的使用限额*/
alter user user_name quota 10m on tablespace_name;
create tablespace xxx [datafile 'path_name/datafile_name'] [size xxx] [extent management local/dictionary] [default storage(xxx)];
exmple: create tablespace userdata datafile '$ORACLE_HOME/oradata/userdata01.dbf' size 100M AUTOEXTEND ON NEXT 5M MAXSIZE 200M;
create tablespace userdata datafile '$ORACLE_HOME/oradata/userdata01.dbf' size 100M extent management dictionary default storage(initial 100k next 100k pctincrease 10) offline;
/*9i以后，oracle建议使用local管理，而不使用dictionary管理，因为local采用bitmap管理表空间 ，不会产生系统表空间的自愿争用;*/
create tablespace userdata datafile '$ORACLE_HOME/oradata/userdata01.dbf' size 100M extent management local uniform size 1m;
create tablespace userdata datafile '$ORACLE_HOME/oradata/userdata01.dbf' size 100M extent management local autoallocate;
/*在创建表空间时，设置表空间内的段空间管理模式，这里用的是自动管理*/
create tablespace userdata datafile '$ORACLE_HOME/oradata/userdata01.dbf' size 100M extent management local uniform size 1m segment space management auto;
alter tablespace userdata mininum extent 10;
alter tablespace userdata default storage(initial 1m next 1m pctincrease 20);
/*undo tablespace(不能被用在字典管理模下) */
create undo tablespace undo1 datafile '$ORACLE_HOME/oradata/undo101.dbf' size 40M extent management local;
show parameter undo;
/*temporary tablespace*/
create temporary tablespace userdata tempfile '$ORACLE_HOME/oradata/undo101.dbf' size 10m extent management local;
/*设置数据库缺省的临时表空间*/
alter database default temporary tablespace tablespace_name;
/*系统/临时/在线的undo表空间不能被offline*/
alter tablespace tablespace_name offline/online;
alter tablespace tablespace_name read only;
/*重命名用户表空间*/
alter tablespace tablespace_name rename datafile '$ORACLE_HOME/oradata/undo101.dbf' to '$ORACLE_HOME/oradata/undo102.dbf';
/*重命名系统表空间 ,但在重命名前必须将数据库shutdown,并重启到mount状态*/
alter database rename file '$ORACLE_HOME/oradata/system01.dbf' to '$ORACLE_HOME/oradata/system02.dbf';
drop tablespace userdata including contents and datafiles;---drop tablespce
/*resize tablespace,autoextend datafile space*/
alter database datafile '$ORACLE_HOME/oradata/undo102.dbf' autoextend on next 10m maxsize 500M;
/*resize datafile*/
alter database datafile '$ORACLE_HOME/oradata/undo102.dbf' resize 50m;
/*给表空间扩展空间*/
alter tablespace userdata add datafile '$ORACLE_HOME/oradata/undo102.dbf' size 10m;
/*将表空间设置成OMF状态*/
alter system set db_create_file_dest='$ORACLE_HOME/oradata';
create tablespace userdata;---use OMF status to create tablespace;
drop tablespace userdata;---user OMF status to drop tablespace;
select * from dba_tablespace/v$tablespace/dba_data_files;
/*将表的某分区移动到另一个表空间*/
alter table table_name move partition partition_name tablespace tablespace_name;
###### ORACLE storage structure and relationships #########
/*手工分配表空间段的分区(extend)大小*/
alter table kong.test12 allocate extent(size 1m datafile '$ORACLE_HOME/oradata/undo102.dbf');
alter table kong.test12 deallocate unused; ---释放表中没有用到的分区
show parameter db;
alter system set db_8k_cache_size=10m; ---配置8k块的内存空间块参数
select * from dba_extents/dba_segments/data_tablespace;
select * from dba_free_space/dba_data_file/data_tablespace;
/*数据对象所占用的字节数*/
select sum(bytes) from dba_extents where onwer='kong' and segment_name ='table_name';
############ UNDO Data ################
show parameter undo;
alter tablespace users offline normal;
alter tablespace users offline immediate;
recover datafile '$ORACLE_HOME/oradata/undo102.dbf';
alter tablespace users online ;
select * from dba_rollback_segs;
alter system set undo_tablespace=undotbs1;
/*忽略回滚段的错误提示*/
alter system set undo_suppress_errors=true;
/*在自动管理模式下,不会真正建立rbs1;在手工管理模式则可以建立,且是私有回滚段*/
create rollback segment rbs1 tablespace undotbs;
desc dbms_flashback;
/*在提交了修改的数据后,9i提供了旧数据的回闪操作,将修改前的数据只读给用户看,但这部分数据不会又恢复在表中,而是旧数据的一个映射*/
execute dbms_flashback.enable_at_time('26-JAN-04:12:17:00 pm');
execute dbms_flashback.disable;
/*回滚段的统计信息*/
select end_time,begin_time,undoblks from v$undostat;
/*undo表空间的大小计算公式: UndoSpace=[UR * (UPS * DBS)] + (DBS * 24)
UR :UNDO_RETENTION 保留的时间(秒)
UPS :每秒的回滚数据块
DBS:系统EXTENT和FILE SIZE(也就是db_block_size)*/
select * from dba_rollback_segs/v$rollname/v$rollstat/v$undostat/v$session/v$transaction;
show parameter transactions;
show parameter rollback;
/*在手工管理模式下,建立公共的回滚段*/
create public rollback segment prbs1 tablespace undotbs;
alter rollback segment rbs1 online;----在手工管理模式
/*在手工管理模式中,initSID.ora中指定 undo_management=manual 、rollback_segment=('rbs1','rbs2',...)、
transactions=100 、transactions_per_rollback_segment=10
然后 shutdown immediate ,startup pfile=....\???.ora */
########## Managing Tables ###########
/*char type maxlen=2000;varchar2 type maxlen=4000 bytes
rowid 是18位的64进制字符串 (10个bytes 80 bits)
rowid组成: object#(对象号)--32bits,6位
rfile#(相对文件号)--10bits,3位
block#(块号)--22bits,6位
row#(行号)--16bits,3位
64进制: A-Z,a-z,0-9,/,+ 共64个符号
dbms_rowid 包中的函数可以提供对rowid的解释*/
select rowid,dbms_rowid.rowid_block_number(rowid),dbms_rowid.rowid_row_number(rowid) from table_name;
create table test2
(
id int,
lname varchar2(20) not null,
fname varchar2(20) constraint ck_1 check(fname like 'k%'),
empdate date default sysdate)
) tablespace tablespace_name;
create global temporary table test2 on commit delete/preserve rows as select * from kong.authors;
create table user.table(...) tablespace tablespace_name storage(...) pctfree10 pctused 40;
alter table user.tablename pctfree 20 pctused 50 storage(...);---changing table storage
/*手工分配分区,分配的数据文件必须是表所在表空间内的数据文件*/
alter table user.table_name allocate extent(size 500k datafile '...');
/*释放表中没有用到的空间*/
alter table table_name deallocate unused;
alter table table_name deallocate unused keep 8k;
/*将非分区表的表空间搬到新的表空间,在移动表空间后，原表中的索引对象将会不可用，必须重建*/
alter table user.table_name move tablespace new_tablespace_name;
create index index_name on user.table_name(column_name) tablespace users;
alter index index_name rebuild;
drop table table_name [CASCADE CONSTRAINTS];
alter table user.table_name drop column col_name [CASCADE CONSTRAINTS CHECKPOINT 1000];---drop column
/*给表中不用的列做标记*/
alter table user.table_name set unused column comments CASCADE CONSTRAINTS;
/*drop表中不用的做了标记列*/
alter table user.table_name drop unused columns checkpoint 1000;
/*当在drop col是出现异常，使用CONTINUE，防止重删前面的column*/
ALTER TABLE USER.TABLE_NAME DROP COLUMNS CONTINUE CHECKPOINT 1000;
select * from dba_tables/dba_objects;