There are changes in this document for recent releases of Oracle Database.
The following are changes in Oracle Database Administrator's Guide for Oracle Database 12c Release 2 (126.96.36.199).
The following features are new in this release:
Oracle Sharding is a scalability and availability feature that supports distribution and replication of data across a pool of discrete Oracle databases that share no hardware or software.
See "Sharded Database Management".
New features for the Oracle Multitenant option:
An application container is an optional component of a multitenant container database (CDB) that consists of an application root and all of the application PDBs associated with it. An application container stores data for one or more applications.
See "Application Containers".
Application common objects
Application common objects are created in an application root and are shared with the application PDBs that belong to the application root.
Support for thousands of pluggable databases (PDBs) in a single CDB
A CDB can contain up to 4,096 PDBs.
Use different character sets for PDBs
When the character set of the CDB root is AL32UTF8, any container in the CDB can use a character set that is different from the CDB root and different from other containers in the CDB.
Relocate a PDB from one CDB to another
A PDB can be relocated in one operation with minimal down time.
A proxy PDB references a PDB in a different CDB and provides fully functional access to the referenced PDB.
Hot PDB cloning
The source PDB can be in open read/write mode during a PDB clone operation.
Rename services during PDB creation
SERVICE_NAME_CONVERT clause of the
CREATE PLUGGABLE DATABASE statement renames the user-defined services of the new PDB based on the service names of the source PDB.
See "Renaming a Service".
Switch to a specific service for a container in a CDB
You can specify a service name in an
ALTER SESSION SET CONTAINER statement.
Manage the memory usage of PDBs in a CDB
You can configure guarantees and limits for SGA and PGA memory, using PDB initialization parameters.
Limit the I/O generated by specific PDBs
Two new initialization parameters,
MAX_MBPS, enable you to limit disk I/O generated by a PDB.
MAX_IOPS limits the number of I/O operations, and
MAX_MBPS limits the megabytes for I/O operations.
PDB performance profiles
You can specify Resource Manager directives for a set of PDBs using PDB performance profiles.
Monitor PDBs managed by Oracle Database Resource Manager
A set of dynamic performance views enables you to monitor the results of your Oracle Database Resource Manager settings for PDBs.
Prioritize PDB upgrades
You can prioritize the PDBs in a CDB when you upgrade the CDB. The PDBs with higher priority are upgraded before PDBs with lower priority.
CDB undo mode
A CDB can run in local undo mode or shared undo mode. Local undo mode means that every container in the CDB uses local undo. Shared undo mode means that there is one active undo tablespace for a single-instance CDB. For an Oracle RAC CDB, there is one active undo tablespace for each instance.
See "Managing the CDB Undo Mode".
Parallelized PDB creation
PARALLEL clause of the
CREATE PLUGGABLE DATABASE statement specifies whether to use parallel execution servers during PDB creation and, optionally, the degree of parallelism.
See "Parallelize PDB Creation".
Unplugging PDBs and plugging in PDBs with an archive file
A PDB can be unplugged into compressed archive of the XML file that describes the PDB and the files used by the PDB (such as the data files and wallet file). The archive file has a .pdb extension, and it can be used to plug the PDB into a CDB or application container.
You can create a PDB as a refreshable clone and refresh the PDB with changes made to the source PDB.
Improved support for default tablespace specification during PDB creation
You can specify a default tablespace for a PDB that is created using techniques such as cloning and plugging in the PDB. Previously, a default tablespace could be specified only if the PDB was created from the CDB seed.
See "Default Tablespace".
USER_TABLESPACES clause during PDB creation
The creation mode of user tablespaces can be different than the creation mode of the PDB. For example, during PDB creation, the user tablespaces can move a tablespace’s files even when file copy is specified for the PDB.
See "User Tablespaces".
Improvements to online redefinition of tables:
In past releases, tables with
BFILE columns could not be redefined online. In Oracle Database 12c Release 2 (188.8.131.52), tables with
BFILE columns can be redefined online.
For online table redefinition that did not change the shape of the table, you can enable rollback of a table to return the table to its original definition and preserve DML changes made to the table.
You can refresh dependent fast refreshable materialized views during online table redefinition by setting the
refresh_dep_mviews parameter to
Y in the
REDEF_TABLE procedure or the
Optimize the performance of bulk updates to a table with the
EXECUTE_UPDATE procedure in the
DBMS_REDEFINITION package. Performance is optimized because the updates are not logged in the redo log.
You can query the
V$ONLINE_REDEF view to monitor the progress of an online table redefinition operation.
When online table redefinition fails, often you can correct the problem that caused the failure and restart the online redefinition process where it last stopped.
Limit PGA usage with Resource Manager
Resource Manager can limit the amount of PGA memory that can be allocated to each session in a particular consumer group.
See "Program Global Area (PGA)".
Improvements in index compression
You can specify a high level of advanced index compression in addition to the low level available in past releases. The high level of advanced index compression saves more space than the low level.
Hybrid Columnar Compression can be enabled for array inserts
Rows inserted with an array insert can be compressed using Hybrid Columnar Compression. In past releases, only rows inserted with a direct-path
INSERT could be compressed using Hybrid Columnar Compression.
See "About Table Compression".
Improvements in table move operations
ONLINE keyword is included in an
ALTER TABLE MOVE statement, data manipulation language (DML) operations are supported during the move operation. Also, indexes are usable during the move operation when the
ONLINE keyword is included and the
UPDATE INDEXES clause is included.
SYSRAC administrative privileges for separation of duties
Oracle Database now provides an new administrative privilege for tasks related to Oracle Real Application Clusters (Oracle RAC) operations.
See "Administrative Privileges".
New database resident connection pooling parameter for long running transactions
To prevent long running transactions from being rolled back because of the limit specified in the
MAX_THINK_TIME parameter, the new parameter
MAX_TXN_THINK_TIME for subprograms in the
DBMS_CONNECTION_POOL package specifies the maximum amount of time, in seconds, for any sessions with a transaction in progress.
Additional information available about the state of each connection in the database resident connection pool
New columns added to the
V$CPOOL_CONN_INFO view provide more information about the current state of each connection in the connection pool.
Improved monitoring for database links
New views and supplied PL/SQL functions enable you to determine the host name of an outgoing database link, view detailed information about information about incoming database links, and determine the source of high system change number (SCN) activity for incoming database links.
Object quarantine isolates an object that has raised an error and monitors the object for impacts on the system.
Delay of instance abort
INSTANCE_ABORT_DELAY_TIME initialization parameter specifies a delay time when an error causes an instance to abort.
See "Delaying Instance Abort".
Oracle Database can prespawn processes for better client connection performance.
Partitioned external tables
For large amounts of data, partitioning for external tables provides fast query performance and enhanced data maintenance.
See "Partitioning External Tables".
The following are changes in Oracle Database Administrator's Guide for Oracle Database 12c Release 1 (184.108.40.206).
The following features are new in this release:
In-Memory Column Store
The In-Memory Column Store (IM column store) in an optional area in the SGA that stores whole tables, table partitions, individual columns, and materialized views in a compressed columnar format. The database uses special techniques to scan columnar data extremely rapidly. The IM column store is a supplement to rather than a replacement for the database buffer cache.
Data Pump Support for the In-Memory Column Store
Data Pump can keep, override, or drop the In-Memory clause for database objects being imported.
Force full database caching mode
To improve performance, you can force an instance to store the database in the buffer cache.
Big Table Cache
The Automatic Big Table Caching feature enables parallel queries to use the buffer cache.
See "Memory Architecture Overview".
Attribute clustering specifies a directive for heap-organized tables to store data in close proximity on disk, providing performance and data storage benefits. This directive is only applicable for direct path operations, such was a bulk insert or a move operation.
A zone is a set of contiguous data blocks on disk. A zone map tracks the minimum and maximum of specified columns for all individual zones. The primary benefit of zone maps is I/O reduction for table scans.
See "Consider Using Zone Maps".
Advanced index compression
Advanced index compression results in excellent compression ratios while still providing efficient access to the indexes. Advanced index compression works at the block level to provide the best compression for each block, which means that users do not require knowledge of data characteristics. Advanced index compression automatically chooses the right compression for each block.
Preserving the open mode of PDBs when the CDB restarts
You can preserve the open mode of one or more PDBs when the CDB restarts by using the
DATABASE SQL statement with a pdb_save_or_discard_state clause.
USER_TABLESPACES clause of the
You can use this clause to separate the data for multiple schemas into different PDBs. For example, when you move a non-CDB to a PDB, and the non-CDB had a number of schemas that each supported different application, you can use this clause to separate the data belonging to each schema into a separate PDB, assuming that each schema used a separate tablespace in the non-CDB.
See "User Tablespaces".
Excluding data when cloning a PDB
NO DATA clause of the
DATABASE statement specifies that a PDB's data model definition is cloned but not the PDB's data.
Default Oracle Managed Files file system directory or Oracle ASM disk group for a PDB's files
CREATE_FILE_DEST clause specifies the default location.
See "File Location of the New PDB".
Create a PDB by cloning a non-CDB
You can create a PDB by cloning a non-CDB with a
CREATE PLUGGABLE DATABASE statement that includes the
The logging_clause of the
ALTER PLUGGABLE DATABASE statement
This clause specifies the logging attribute of the PDB. The logging attribute controls whether certain DML operations are logged in the redo log file (
LOGGING) or not (
See "PDB Tablespace Logging" for information about this clause and the
CREATE PLUGGABLE DATABASE statement. See "Modifying a PDB with the ALTER PLUGGABLE DATABASE Statement" for information about this clause and the
ALTER PLUGGABLE DATABASE statement.
The pdb_force_logging_clause of the
ALTER PLUGGABLE DATABASE statement
This clause places a PDB into force logging or force nologging mode or takes a PDB out of force logging or force nologging mode.
STANDBYS clause of the
This clause specifies whether the new PDB is included in standby CDBs.
Querying user-created tables and views across all PDBs
CONTAINERS clause enables you to query user-created tables and views across all PDBs in a CDB.
Oracle Clusterware support for the Diagnosability Framework
Oracle Clusterware uses the Diagnosability Framework and ADR for recording diagnostic trace data and the Clusterware alert log.
READ object privilege and
TABLE system privilege
READ privilege on an object enables a user to select from an object without providing the user with any other privileges.
The following are changes in Oracle Database Administrator's Guide for Oracle Database 12c Release 1 (220.127.116.11).
The following features are new in this release:
Oracle Multitenant option
Oracle Multitenant option enables an Oracle database to function as a multitenant container database (CDB) that includes one or many customer-created pluggable databases (PDBs). A PDB is a portable collection of schemas, schema objects, and nonschema objects that appears to an Oracle Net client as a non-CDB. All Oracle databases before Oracle Database 12c were non-CDBs. You can unplug a PDB from a CDB and plug it into a different CDB.
Resource Manager support for a multitenant environment
Resource Manager can manage resources on the CDB level and on the PDB level. You can create a CDB resource plan that allocates resources to the entire CDB and to individual PDBs. You can allocate more resources to some PDBs and less to others, or you can specify that all PDBs share resources equally.
Full transportable export/import
Full transportable export/import enables you to move a database from one database instance to another. Transporting a database is much faster than other methods that move a database, such as full database export/import. In addition, you can use full transportable export/import to move a non-CDB (or an Oracle Database 11g Release 2 (18.104.22.168) database) into a PDB that is part of a CDB.
See Transporting Data.
New administrative privileges for separation of duties
Oracle Database now provides administrative privileges for tasks related to Oracle Recovery Manager (Oracle RMAN), Oracle Data Guard, and Transparent Data Encryption. Each new administrative privilege grants the minimum required privileges to complete tasks in each area of administration. The new administrative privileges enable you to avoid granting
SYSDBA administrative privilege for many common tasks.
Database Smart Flash Cache support for multiple flash devices
A database instance can access and combine multiple flash devices for Database Smart Flash Cache without requiring a volume manager.
Undo for temporary objects is stored in a temporary tablespace, not in the undo tablespace. Using temporary undo reduces the amount of undo stored in the undo tablespace and the size of the redo log. It also enables data manipulation language (DML) operations on temporary tables in a physical standby database with the Oracle Active Data Guard option.
Move a data file online
You can move a data file when the data file is online and being accessed. This capability simplifies maintenance operations, such as moving data to a different storage device.
Multiple indexes on the same set of columns
You can create multiple indexes on the same set of columns to perform application migrations without dropping an existing index and recreating it with different attributes.
Move a partition or subpartition online
DML operations can continue to run uninterrupted on a partition or subpartition that is being moved without using online table redefinition.
Online redefinition of a table in one step
You can use the
REDEF_TABLE procedure in the
DBMS_REDEFINITION package to perform online redefinition of a table's storage properties in a single call to the procedure.
Online redefinition of tables with multiple partitions
To minimize downtime when redefining multiple partitions in a table, you can redefine these partitions online in a single session.
Online redefinition of tables with Virtual Private Database (VPD) policies
To minimize downtime, tables with VPD policies can be redefined online.
New time limit parameter in the
dml_lock_timeout parameter in the
FINISH_REDEF_TABLE procedure in the
DBMS_REDEFINITION package can specify how long the procedure waits for pending DML to commit.
You can make individual table columns invisible. Any generic access of a table does not show the invisible columns in the table.
See "Understand Invisible Columns".
COLUMN with default value for nullable columns
A nullable column is a column created without using the
NULL constraint. For certain types of tables, when adding a nullable column that has a default value, the database can optimize the resource usage and storage requirements for the operation. It does so by storing the default value for the new column as table metadata, avoiding the need to store the value in all existing records.
See "Adding Table Columns".
Copy-on-write cloning of a database with CloneDB
When cloning a database with CloneDB, Oracle Database can create the files in a CloneDB database based on copy-on-write technology, so that only the blocks that are modified in the CloneDB database require additional storage on disk.
When the logging of DDL statements is enabled, DDL statements are recorded in a separate DDL log instead of the alert log.
See "DDL Log".
Some information that can be used to debug a problem is recorded in a separate debug log instead of the alert log.
See "Debug Log".
Full-word options for the Server Control (SRVCTL) utility
For improved usability, each SRVCTL utility option is a full word instead of single letter.
Transaction Guard and Application Continuity
Transaction Guard ensures at-most-once execution of transactions to protect applications from duplicate transaction submissions and associated logical errors. Transaction Guard enables Application Continuity, which is the ability to replay transactions and continue processing after recoverable communication errors.
Enhanced statement queuing
Critical statements can bypass the parallel statement queue. You can set the resource plan directive
BYPASS_QUEUE for a high-priority consumer group so that parallel statements from the consumer group bypass the parallel statement queue.
New Job Types
Several new script jobs have been added that permit running custom user scripts using SQL*Plus, the RMAN interpreter, or a command shell for the computer platform.
See "Script Jobs".
The following features are deprecated in this release and may be desupported in a future release:
IGNORECASE argument of ORAPWD
To support strong authentication, Oracle recommends that you set
n or omit
IGNORECASE entirely. The default value of this optional ORAPWD argument is
See "Creating a Database Password File with ORAPWD" for further information.
Single-character options with Server Control (SRVCTL) utility commands
All SRVCTL commands have been enhanced to accept full-word options instead of the single-letter options. All new SRVCTL command options added in this release support full-word options only and do not have single-letter equivalents. The use of single-character options with SRVCTL commands might be desupported in a future release.
See "SRVCTL Command Reference for Oracle Restart" for further information.
FILE_MAPPING initialization parameter
FILE_MAPPING initialization parameter is deprecated. It is still supported for backward compatibility.
See Oracle Database Reference for information about the
FILE_MAPPING initialization parameter.
This view continues to be available for backward compatibility.
See "Specifying Scheduler Job Credentials" for further information.