Tablespace creation management and control file management

Table space is a logical concept , Physically corresponding to one or more data files datafile Or temporary files tempfiles, Logically, table spaces are containers for storage segments .（ Segment is also a logical concept , Are objects in the database, such as tables 、 Index, etc. ）

Tablespace type

①PERMANENT Permanent table space

②UNDO Undo tablespace

③TEMPORARY Temporary table space

The management mode focuses on the management mode of sections and districts , It is determined when establishing the table space .

1.1 View tablespace types 、 Section and area management mode

[email protected]> select tablespace_name,contents,segment_space_management,extent_management from dba_tablespaces;

TABLESPACE_NAME                CONTENTS  SEGMEN EXTENT_MAN
------------------------------ --------- ------ ----------
SYSTEM                         PERMANENT MANUAL LOCAL
SYSAUX                         PERMANENT AUTO   LOCAL
UNDOTBS1                       UNDO      MANUAL LOCAL
TEMPTS1                        TEMPORARY MANUAL LOCAL
USERS                          PERMANENT MANUAL LOCAL

[email protected]> select * from v$tablespace;

       TS# NAME                           INC BIG FLA ENC
---------- ------------------------------ --- --- --- ---
         0 SYSTEM                         YES NO  YES
         1 SYSAUX                         YES NO  YES
         2 UNDOTBS1                       YES NO  YES
         3 TEMPTS1                        NO  NO  YES
         4 USERS                          YES NO  YES

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1.2 View tablespaces ( Data files ) size 、 Whether to automatically expand

select file_id,file_name,tablespace_name,bytes/1024/1024 M,status,
AUTOEXTENSIBLE from dba_data_files order by 1;

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1.3 View tablespace size

select TABLESPACE_NAME,sum(bytes)/1024/1024 from dba_data_files group by tablespace_name;

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1.4 Check the free size of the table space

select tablespace_name,sum(bytes)/1024/1024 from dba_free_space group by tablespace_name;

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1.5 establish smallfile Table space

The size of the table space is equal to the sum of the sizes of the data files under it , By default small Table space

Commonly used when there is a problem of insufficient table space 3 There is a solution ：

1） Increase the size of the original data file （resize）

2） Add a data file （add datafile）

3） Set the table space to grow automatically （autoextend)

create tablespace test datafile '/u01/app/oracle/oradata/orcl/test01.dbf' size 5m;

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1.5.1 resize Expand the table space

select file_id,file_name,tablespace_name from dba_data_files;
alter database datafile 6 resize 10m;

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1.5.2 add datafile Expand the table space ：

alter tablespace test add datafile '/u01/app/oracle/oradata/orcl/test02.dbf' size 30G;

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1.5.3 autoextend on Expand the table space

alter database datafile 6 autoextend on maxsize 30G;
select FILE_ID,TABLESPACE_NAME,BYTES/1024/1024 M_size,
AUTOEXTENSIBLE,MAXBYTES/1024/1024 M_max from dba_data_files;

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1.6 Create large files （bigfile） Table space

①smallfile： A table space can contain multiple data files （ Default ）, Block size 8k when , The size should be less than 32G.

②bigfile： A table space contains only one data file , 8k Of block when , Up to 32T.

create bigfile tablespace bigtbs
datafile '/u01/app/oracle/oradata/orcl/bigtbs01.dbf' size 20m
autoextend on maxsize 4T
extent management local uniform size 2m
segment space management auto;

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1.61. View large tablespace files

select name,bigfile from v$tablespace;

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1.7 Delete tablespace

drop tablespace test including contents and datafiles;
drop tablespace bigtbs including contents and datafiles;

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2. Control documents

2.1 Functions and features ：

1） Record the current physical state of the database

2） Maintain database consistency

3） It's a small binary file

4） stay mount The stage is read

5） Record RMAN Backup metadata

select name from v$datafile;
select member from v$logfile;

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View control file location ：

show parameter control_files;
select name from v$controlfile;

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2.2 Real time update mechanism

① When you add 、 rename 、 When deleting a data file or an online log file , Oracle Server process （Server

Process） The control file is immediately updated to reflect changes in the database structure .

② Log writing process LGWR Responsible for recording the current log serial number in the control file .

③ Checkpoint process CKPT Be responsible for recording the information of verification point in the control file .

④ Archiving process ARCN Be responsible for recording the information in the archive log into the control file .

Through view v$controlfile_record_section It can be learned that a large number of current database status information is recorded in the control file

2.3 Control file multiplexing

2.3.1 modify spfile Medium control_files Parameters

[email protected]>create pfile from spfile;
[email protected]>select name from v$controlfile;
[email protected]>alter system set control_files='/u01/app/oracle/oradata/PROD1/control01.ctl',
'/u01/app/oracle/oradata/PROD1/control02.ctl','/u01/app/oracle/oradata/PROD1/control03.ctl' scope=spfile;

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2.3.2 Normal shutdown , Boot to nomount Status view

[email protected]>shutdown immediate;
[email protected]>startup nomount;
[email protected]>show parameter control_files

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2.3.3 Copy control file , It is recommended to allocate to different physical disks

[email protected]>! cp /u01/app/oracle/oradata/PROD1/control02.ctl /u01/app/oracle/oradata/PROD1/control03.ctl

[email protected]> alter database mount;
[email protected]> alter database open;

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