Oracle® Database SQL Language Reference 11g Release 2 (11.2) Part Number E10592-02 |
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Purpose
Use the CREATE
TABLESPACE
statement to create a tablespace, which is an allocation of space in the database that can contain schema objects.
A permanent tablespace contains persistent schema objects. Objects in permanent tablespaces are stored in data files.
An undo tablespace is a type of permanent tablespace used by Oracle Database to manage undo data if you are running your database in automatic undo management mode. Oracle strongly recommends that you use automatic undo management mode rather than using rollback segments for undo.
A temporary tablespace contains schema objects only for the duration of a session. Objects in temporary tablespaces are stored in temp files.
When you create a tablespace, it is initially a read/write tablespace. You can subsequently use the ALTER
TABLESPACE
statement to take the tablespace offline or online, add data files or temp files to it, or make it a read-only tablespace.
You can also drop a tablespace from the database with the DROP
TABLESPACE
statement.
See Also:
Oracle Database Concepts for information on tablespaces
ALTER TABLESPACE and DROP TABLESPACE for information on modifying and dropping tablespaces
Additional Topics
Prerequisites
You must have the CREATE
TABLESPACE
system privilege. To create the SYSAUX
tablespace, you must have the SYSDBA
system privilege.
Before you can create a tablespace, you must create a database to contain it, and the database must be open.
See Also:
CREATE DATABASETo use objects in a tablespace other than the SYSTEM
tablespace:
If you are running the database in automatic undo management mode, then at least one UNDO
tablespace must be online.
If you are running the database in manual undo management mode, then at least one rollback segment other than the SYSTEM
rollback segment must be online.
Note:
Oracle strongly recommends that you run your database in automatic undo management mode. For more information, refer to Oracle Database Administrator's Guide.Syntax
create_tablespace::=
(permanent_tablespace_clause::=, temporary_tablespace_clause::=, undo_tablespace_clause::=)
permanent_tablespace_clause::=
(file_specification::=, size_clause::=, logging_clause ::=, encryption_spec::=, table_compression::=—part of CREATE
TABLE
, storage_clause::=, extent_management_clause ::=, segment_management_clause ::=, flashback_mode_clause ::=)
logging_clause ::=
temporary_tablespace_clause::=
(file_specification::=, tablespace_group_clause, extent_management_clause ::=)
(file_specification::=, extent_management_clause ::=, tablespace_retention_clause ::=)
tablespace_retention_clause ::=
Semantics
Use this clause to determine whether the tablespace is a bigfile or smallfile tablespace. This clause overrides any default tablespace type setting for the database.
A bigfile tablespace contains only one data file or temp file, which can contain up to approximately 4 billion (232) blocks. The maximum size of the single data file or temp file is 128 terabytes (TB) for a tablespace with 32K blocks and 32TB for a tablespace with 8K blocks.
A smallfile tablespace is a traditional Oracle tablespace, which can contain 1022 data files or temp files, each of which can contain up to approximately 4 million (222) blocks.
If you omit this clause, then Oracle Database uses the current default tablespace type of permanent or temporary tablespace set for the database. If you specify BIGFILE
for a permanent tablespace, then the database by default creates a locally managed tablespace with automatic segment-space management.
Restrictions on Bigfile Tablespaces Bigfile tablespaces are subject to the following restrictions:
You can specify only one data file in the DATAFILE
clause or one temp file in the TEMPFILE
clause.
You cannot specify EXTENT
MANAGEMENT
DICTIONARY
.
See Also:
Oracle Database Administrator's Guide for more information on using bigfile tablespaces
permanent_tablespace_clause
Use the following clauses to create a permanent tablespace. (Some of these clauses are also used to create a temporary or undo tablespace.)
tablespace
Specify the name of the tablespace to be created.
Note on the SYSAUX Tablespace SYSAUX
is a required auxiliary system tablespace. You must use the CREATE
TABLESPACE
statement to create the SYSAUX
tablespace if you are upgrading from a release prior to Oracle Database 11g. You must have the SYSDBA
system privilege to specify this clause, and you must have opened the database in MIGRATE
mode.
You must specify EXTENT
MANAGEMENT
LOCAL
and SEGMENT
SPACE
MANAGEMENT
AUTO
for the SYSAUX
tablespace. The DATAFILE
clause is optional only if you have enabled Oracle-managed files. See "DATAFILE | TEMPFILE Clause" for the behavior of the DATAFILE
clause.
Take care to allocate sufficient space for the SYSAUX
tablespace. For guidelines on creating this tablespace, refer to Oracle Database Upgrade Guide.
Restrictions on the SYSAUX Tablespace You cannot specify OFFLINE
or TEMPORARY
for the SYSAUX
tablespace.
Specify the data files to make up the permanent tablespace or the temp files to make up the temporary tablespace. Use the datafile_tempfile_spec
form of file_specification
to create regular data files and temp files in an operating system file system or to create Oracle Automatic Storage Management (Oracle ASM) disk group files.
You must specify the DATAFILE
or TEMPFILE
clause unless you have enabled Oracle-managed files by setting a value for the DB_CREATE_FILE_DEST
initialization parameter. For Oracle ASM disk group files, the parameter must be set to a multiple file creation form of Oracle ASM filenames. If this parameter is set, then the database creates a system-named 100 MB file in the default file destination specified in the parameter. The file has AUTOEXTEND
enabled and an unlimited maximum size.
Note: Media recovery does not recognize temp files. |
See Also:
Oracle Database Storage Administrator's Guide for more information on using Oracle ASM
file_specification for a full description, including the AUTOEXTEND
parameter and the multiple file creation form of Oracle ASM filenames
Notes on Specifying Data Files and Temp Files
For operating systems that support raw devices, the REUSE
keyword of datafile_tempfile_spec
has no meaning when specifying a raw device as a data file. Such a CREATE
TABLESPACE
statement will succeed whether or not you specify REUSE
.
You can create a tablespace within an Oracle ASM disk group by providing only the disk group name in the datafile_tempfile_spec
. In this case, Oracle ASM creates a data file in the specified disk group with a system-generated filename. The data file is auto-extensible with an unlimited maximum size and a default size of 100 MB. You can use the autoextend_clause
to override the default size.
If you use one of the reference forms of the ASM_filename
, which refers to an existing file, then you must also specify REUSE
.
Note:
On some operating systems, Oracle does not allocate space for a temp file until the temp file blocks are actually accessed. This delay in space allocation results in faster creation and resizing of temp files, but it requires that sufficient disk space is available when the temp files are later used. To avoid potential problems, before you create or resize a temp file, ensure that the available disk space exceeds the size of the new temp file or the increased size of a resized temp file. The excess space should allow for anticipated increases in disk space use by unrelated operations as well. Then proceed with the creation or resizing operation.See Also:
file_specification for a full description, including the AUTOEXTEND
parameter
"Enabling Autoextend for a Tablespace: Example" and "Creating Oracle-managed Files: Examples"
This clause is valid only for a dictionary-managed tablespace. Specify the minimum size of an extent in the tablespace. This clause lets you control free space fragmentation in the tablespace by ensuring that the size of every used or free extent in a tablespace is at least as large as, and is a multiple of, the value specified in the size_clause
.
See Also:
size_clause for information on that clause and Oracle Database VLDB and Partitioning Guide for more information about usingMINIMUM
EXTENT
to control fragmentationUse the BLOCKSIZE
clause to specify a nonstandard block size for the tablespace. In order to specify this clause, the DB_CACHE_SIZE
and at least one DB_
n
K_CACHE_SIZE
parameter must be set, and the integer you specify in this clause must correspond with the setting of one DB_
n
K_CACHE_SIZE
parameter setting.
Restriction on BLOCKSIZE You cannot specify nonstandard block sizes for a temporary tablespace or if you intend to assign this tablespace as the temporary tablespace for any users.
Note:
Oracle recommend that you do not store tablespaces with a 2K block size on 4K sector size disks, because performance degradation can result.See Also:
Oracle Database Reference for information on theDB_
n
K_CACHE_SIZE
parameter and Oracle Database Concepts for information on multiple block sizesSpecify the default logging attributes of all tables, indexes, materialized views, materialized view logs, and partitions within the tablespace. LOGGING
is the default. This clause is not valid for a temporary or undo tablespace.
The tablespace-level logging attribute can be overridden by logging specifications at the table, index, materialized view, materialized view log, and partition levels.
See Also:
logging_clause for a full description of this clauseUse this clause to put the tablespace into FORCE
LOGGING
mode. Oracle Database will log all changes to all objects in the tablespace except changes to temporary segments, overriding any NOLOGGING
setting for individual objects. The database must be open and in READ
WRITE
mode.
This setting does not exclude the NOLOGGING
attribute. You can specify both FORCE
LOGGING
and NOLOGGING
. In this case, NOLOGGING
is the default logging mode for objects subsequently created in the tablespace, but the database ignores this default as long as the tablespace or the database is in FORCE
LOGGING
mode. If you subsequently take the tablespace out of FORCE
LOGGING
mode, then the NOLOGGING
default is once again enforced.
Note:
FORCE
LOGGING
mode can have performance effects. Please refer to Oracle Database Administrator's Guide for information on when to use this setting.Restriction on Forced Logging You cannot specify FORCE
LOGGING
for an undo or temporary tablespace.
Use this clause to specify the encryption properties of the tablespace. This clause does not actually encrypt the tablespace. You must also specify the ENCRYPT
keyword as part of the DEFAULT
storage_clause
in this statement in order for the tablespace to be encrypted. In addition, you must already have used the ALTER
SYSTEM
... SET
ENCRYPTION
WALLET
clause to load information from the server wallet into memory for database access. For more information, see "SET ENCRYPTION WALLET Clause".
Note:
You cannot decrypt a tablespace that has been created encrypted. You must create an unencrypted tablespace and re-create the database objects in the unencrypted tablespace.encryption_spec The encryption properties are specified in encryption_spec
. The only clause of encryption_spec
that is relevant for tablespace encryption is the USING
clause. Specify USING
'encrypt_algorithm
' to indicate the name of the algorithm to be used. Valid algorithms are 3DES168
, AES128
, AES192
, and AES256
. If you omit this clause, then the database uses AES128
.
This clause lets you specify default storage parameters for all objects created in the tablespace and default compression of data for all tables created in the tablespace. This clause is not valid for a temporary tablespace.
For a dictionary-managed tablespace, the only storage parameter you can specify with this clause is COMPRESS
.
See Also:
storage_clause for information on storage parameters and CREATE
TABLE
... table_compression for information about table compression
ONLINE | OFFLINE Clauses
Use these clauses to determine whether the tablespace is online or offline. This clause is not valid for a temporary tablespace.
ONLINE Specify ONLINE
to make the tablespace available immediately after creation to users who have been granted access to the tablespace. This is the default.
OFFLINE Specify OFFLINE
to make the tablespace unavailable immediately after creation.
The data dictionary view DBA_TABLESPACES
indicates whether each tablespace is online or offline.
The extent_management_clause
lets you specify how the extents of the tablespace will be managed.
Note:
After you have specified extent management with this clause, you can change extent management only by migrating the tablespace.AUTOALLOCATE
specifies that the tablespace is system managed. Users cannot specify an extent size. You cannot specify AUTOALLOCATE
for a temporary tablespace.
UNIFORM
specifies that the tablespace is managed with uniform extents of SIZE
bytes.The default SIZE
is 1 megabyte. All extents of temporary tablespaces are of uniform size, so this keyword is optional for a temporary tablespace. However, you must specify UNIFORM
in order to specify SIZE
. You cannot specify UNIFORM
for an undo tablespace.
If you do not specify the extent_management_clause
, then Oracle Database interprets the MINIMUM
EXTENT
clause and the DEFAULT
storage_clause
to determine extent management.
See Also:
Oracle Database Concepts for a discussion of locally managed tablespacesRestrictions on Extent Management Extent management is subject to the following restrictions:
A permanent locally managed tablespace can contain only permanent objects. If you need a locally managed tablespace to store temporary objects, for example, if you will assign it as a user's temporary tablespace, then use the temporary_tablespace_clause
.
If you specify this clause, then you cannot specify DEFAULT
storage_clause,
MINIMUM
EXTENT
, or the temporary_tablespace_clause
.
See Also:
Oracle Database Administrator's Guide for information on changing extent management by migrating tablespaces and "Creating a Locally Managed Tablespace: Example"The segment_management_clause
is relevant only for permanent, locally managed tablespaces. It lets you specify whether Oracle Database should track the used and free space in the segments in the tablespace using free lists or bitmaps. This clause is not valid for a temporary tablespace.
AUTO Specify AUTO
if you want the database to manage the free space of segments in the tablespace using a bitmap. If you specify AUTO
, then the database ignores any specification for PCTUSED
, FREELIST
, and FREELIST
GROUPS
in subsequent storage specifications for objects in this tablespace. This setting is called automatic segment-space management and is the default.
MANUAL Specify MANUAL
if you want the database to manage the free space of segments in the tablespace using free lists. Oracle strongly recommends that you do not use this setting and that you create tablespaces with automatic segment-space management.
To determine the segment management of an existing tablespace, query the SEGMENT_SPACE_MANAGEMENT
column of the DBA_TABLESPACES
or USER_TABLESPACES
data dictionary view.
Notes:
If you specifyAUTO
segment management, then:
If you set extent management to LOCAL
UNIFORM
, then you must ensure that each extent contains at least 5 database blocks.
If you set extent management to LOCAL
AUTOALLOCATE
, and if the database block size is 16K or greater, then Oracle manages segment space by creating extents with a minimum size of 5 blocks rounded up to 64K.
Restrictions on Automatic Segment-space Management This clause is subject to the following restrictions:
You can specify this clause only for a permanent, locally managed tablespace.
You cannot specify this clause for the SYSTEM
tablespace.
See Also:
Oracle Database Storage Administrator's Guide for information on automatic segment-space management and when to use it
Oracle Database Reference for information on the data dictionary views
"Specifying Segment Space Management for a Tablespace: Example"
Use this clause in conjunction with the ALTER
DATABASE
FLASHBACK
clause to specify whether the tablespace can participate in FLASHBACK
DATABASE
operations. This clause is useful if you have the database in FLASHBACK
mode but you do not want Oracle Database to maintain Flashback log data for this tablespace.
This clause is not valid for temporary or undo tablespaces.
FLASHBACK ON Specify FLASHBACK
ON
to put the tablespace in FLASHBACK
mode. Oracle Database will save Flashback log data for this tablespace and the tablespace can participate in a FLASHBACK
DATABASE
operation. If you omit the flashback_mode_clause
, then FLASHBACK
ON
is the default.
FLASHBACK OFF Specify FLASHBACK
OFF
to take the tablespace out of FLASHBACK
mode. Oracle Database will not save any Flashback log data for this tablespace. You must take the data files in this tablespace offline or drop them prior to any subsequent FLASHBACK
DATABASE
operation. Alternatively, you can take the entire tablespace offline. In either case, the database does not drop existing Flashback logs.
Note:
TheFLASHBACK
mode of a tablespace is independent of the FLASHBACK
mode of an individual table.See Also:
Oracle Database Backup and Recovery User's Guide for information on Oracle Flashback Database
ALTER DATABASE and FLASHBACK DATABASE for information on setting the FLASHBACK
mode of the entire database and reverting the database to an earlier version
Use this clause to create a locally managed temporary tablespace, which is an allocation of space in the database that can contain transient data that persists only for the duration of a session. This transient data cannot be recovered after process or instance failure.
The transient data can be user-generated schema objects such as temporary tables or system-generated data such as temp space used by hash joins and sort operations. When a temporary tablespace, or a tablespace group of which this tablespace is a member, is assigned to a particular user, then Oracle Database uses the tablespace for sorting operations in transactions initiated by that user.
The TEMPFILE
clause is described in "DATAFILE | TEMPFILE Clause". The extent_management_clause
is described in extent_management_clause .
See Also:
Oracle Database Security Guide for information on assigning temporary tablespaces to userstablespace_group_clause
This clause is relevant only for temporary tablespaces. Use this clause to determine whether tablespace
is a member of a tablespace group. A tablespace group lets you assign multiple temporary tablespaces to a single user and increases the addressability of temporary tablespaces.
Specify a group name to indicate that tablespace
is a member of this tablespace group. The group name cannot be the same as tablespace
or any other existing tablespace. If the tablespace group already exists, then Oracle Database adds the new tablespace to that group. If the tablespace group does not exist, then the database creates the group and adds the new tablespace to that group.
Specify an empty string (' ') to indicate that tablespace
is not a member of any tablespace group.
See Also:
ALTER TABLESPACE and "Adding a Temporary Tablespace to a Tablespace Group: Example" for information on adding a tablespace to a tablespace group
CREATE USER for information on assigning a temporary tablespace to a user
Oracle Database Administrator's Guide for more information on tablespace groups
Restrictions on Temporary Tablespaces The data stored in temporary tablespaces persists only for the duration of a session. Therefore, only a subset of the CREATE
TABLESPACE
clauses are relevant for temporary tablespaces. The only clauses you can specify for a temporary tablespace are the TEMPFILE
clause, the tablespace_group_clause
, and the extent_management_clause
.
Specify UNDO
to create an undo tablespace. When you run the database in automatic undo management mode, Oracle Database manages undo space using the undo tablespace instead of rollback segments. This clause is useful if you are now running in automatic undo management mode but your database was not created in automatic undo management mode.
Oracle Database always assigns an undo tablespace when you start up the database in automatic undo management mode. If no undo tablespace has been assigned to this instance, then the database uses the SYSTEM
rollback segment. You can avoid this by creating an undo tablespace, which the database will implicitly assign to the instance if no other undo tablespace is currently assigned.
The DATAFILE
clause is described in "DATAFILE | TEMPFILE Clause". The extent_management_clause
is described in extent_management_clause .
This clause is valid only for undo tablespaces.
RETENTION
GUARANTEE
specifies that Oracle Database should preserve unexpired undo data in all undo segments of tablespace
even if doing so forces the failure of ongoing operations that need undo space in those segments. This setting is useful if you need to issue an Oracle Flashback Query or an Oracle Flashback Transaction Query to diagnose and correct a problem with the data.
RETENTION
NOGUARANTEE
returns the undo behavior to normal. Space occupied by unexpired undo data in undo segments can be consumed if necessary by ongoing transactions. This is the default.
Restrictions on Undo Tablespaces Undo tablespaces are subject to the following restrictions:
You cannot create database objects in this tablespace. It is reserved for system-managed undo data.
The only clauses you can specify for an undo tablespace are the DATAFILE
clause and the extent_management_clause
to specify local extent management. You cannot specify dictionary extent management using the extent_management_clause
. All undo tablespaces are created permanent, read/write, and in logging mode. Values for MINIMUM
EXTENT
and DEFAULT
STORAGE
are system generated.
See Also:
Oracle Database Administrator's Guide for information on automatic undo management and undo tablespaces and Oracle Database Reference for information on the UNDO_MANAGEMENT
parameter
CREATE DATABASE for information on creating an undo tablespace during database creation, and ALTER TABLESPACE and DROP TABLESPACE
Examples
These examples assume that your database is using 8K blocks.
Creating a Bigfile Tablespace: Example The following example creates a bigfile tablespace bigtbs_01
with a data file bigtbs_f1.dat
of 20 MB:
CREATE BIGFILE TABLESPACE bigtbs_01 DATAFILE 'bigtbs_f1.dat' SIZE 20M AUTOEXTEND ON;
Creating an Undo Tablespace: Example The following example creates a 10 MB undo tablespace undots1
:
CREATE UNDO TABLESPACE undots1 DATAFILE 'undotbs_1a.f' SIZE 10M AUTOEXTEND ON RETENTION GUARANTEE;
Creating a Temporary Tablespace: Example This statement shows how the temporary tablespace that serves as the default temporary tablespace for database users in the sample database was created:
CREATE TEMPORARY TABLESPACE temp_demo TEMPFILE 'temp01.dbf' SIZE 5M AUTOEXTEND ON;
Assuming that the default database block size is 2K, and that each bit in the map represents one extent, then each bit maps 2,500 blocks.
The following example sets the default location for data file creation and then creates a tablespace with an Oracle-managed temp file in the default location. The temp file is 100 M and is autoextensible with unlimited maximum size. These are the default values for Oracle-managed files:
ALTER SYSTEM SET DB_CREATE_FILE_DEST = '$ORACLE_HOME/rdbms/dbs'; CREATE TEMPORARY TABLESPACE tbs_05;
Adding a Temporary Tablespace to a Tablespace Group: Example The following statement creates the tbs_temp_02
temporary tablespace as a member of the tbs_grp_01
tablespace group. If the tablespace group does not already exist, then Oracle Database creates it during execution of this statement:
CREATE TEMPORARY TABLESPACE tbs_temp_02 TEMPFILE 'temp02.dbf' SIZE 5M AUTOEXTEND ON TABLESPACE GROUP tbs_grp_01;
Creating Basic Tablespaces: Examples This statement creates a tablespace named tbs_01
with one data file:
CREATE TABLESPACE tbs_01 DATAFILE 'tbs_f2.dat' SIZE 40M ONLINE;
This statement creates tablespace tbs_03
with one data file and allocates every extent as a multiple of 500K:
CREATE TABLESPACE tbs_03 DATAFILE 'tbs_f03.dbf' SIZE 20M LOGGING;
Enabling Autoextend for a Tablespace: Example This statement creates a tablespace named tbs_02
with one data file. When more space is required, 500 kilobyte extents will be added up to a maximum size of 100 megabytes:
CREATE TABLESPACE tbs_02 DATAFILE 'diskb:tbs_f5.dat' SIZE 500K REUSE AUTOEXTEND ON NEXT 500K MAXSIZE 100M;
Creating a Locally Managed Tablespace: Example The following statement assumes that the database block size is 2K.
CREATE TABLESPACE tbs_04 DATAFILE 'file_1.f' SIZE 10M EXTENT MANAGEMENT LOCAL UNIFORM SIZE 128K;
This statement creates a locally managed tablespace in which every extent is 128K and each bit in the bit map describes 64 blocks.
The following statement creates a locally managed tablespace with uniform extents and shows an example of a table stored in that tablespace:
CREATE TABLESPACE lmt1 DATAFILE 'lmt_file2.f' SIZE 100m REUSE EXTENT MANAGEMENT LOCAL UNIFORM SIZE 1M; CREATE TABLE lmt_table1 (col1 NUMBER, col2 VARCHAR2(20)) TABLESPACE lmt1 STORAGE (INITIAL 2m);
The initial size of the segment is 5M.
The following example creates a locally managed tablespace without uniform extents:
CREATE TABLESPACE lmt2 DATAFILE 'lmt_file3.f' SIZE 100m REUSE EXTENT MANAGEMENT LOCAL; CREATE TABLE lmt_table2 (col1 NUMBER, col2 VARCHAR2(20)) TABLESPACE lmt2 STORAGE (INITIAL 2m MAXSIZE 100m);
The initial segment size if the table is 5M. Oracle Database determines the size of each extent and the total number of extents allocated to satisfy the initial segment size. The segment's maximum size is limited to 100M.
Creating an Encrypted Tablespace: Example The following statement creates an encrypted tablespace. Encryption must first be enabled for the database by opening the wallet:
ALTER SYSTEM SET ENCRYPTION KEY IDENTIFIED BY "password";
System altered.
CREATE TABLESPACE encrypt_ts
DATAFILE '$ORACLE_HOME/dbs/encrypt_df.dat' SIZE 1M
ENCRYPTION USING '3DES168'
DEFAULT STORAGE (ENCRYPT);
Tablespace created.
Specifying Segment Space Management for a Tablespace: Example The following example creates a tablespace with automatic segment-space management:
CREATE TABLESPACE auto_seg_ts DATAFILE 'file_2.f' SIZE 1M EXTENT MANAGEMENT LOCAL SEGMENT SPACE MANAGEMENT AUTO;
Creating Oracle-managed Files: Examples The following example sets the default location for data file creation and creates a tablespace with a data file in the default location. The data file is 100M and is autoextensible with an unlimited maximum size:
ALTER SYSTEM SET DB_CREATE_FILE_DEST = '$ORACLE_HOME/rdbms/dbs'; CREATE TABLESPACE omf_ts1;
The following example creates a tablespace with an Oracle-managed data file of 100M that is not autoextensible:
CREATE TABLESPACE omf_ts2 DATAFILE AUTOEXTEND OFF;