There are changes in this document for recent releases of Oracle Database.
Changes in Oracle Database 18c
The following are changes in Oracle Database Administrator's Guide for Oracle Database 18c:
The following features are new in this release:
Shadow lost write protection
Shadow lost write protection provides fast detection and immediate response to a lost write. Using shadow lost write protection can minimize data loss and the time required to repair a database. You can enable shadow lost write protection for a database, a tablespace, or a data file without requiring an Oracle Data Guard standby database.
New default location for Oracle Database password file
The default location for Oracle Database password file is
ORACLE_BASEdirectory instead of
ORACLE_HOMEdirectory. This change supports read-only Oracle homes.
Private temporary tables
Private temporary tables are stored in memory and each one is visible only to the session that created it.
See "Creating a Temporary Table".
Inline external tables
Inline external tables enable the runtime definition of an external table as part of a SQL statement, without creating the external table as persistent object in the data dictionary.
See "Using Inline External Tables".
Parallel queue timeout
You can specify the action to be taken on a timed out parallel SQL statement by setting the
PQ_TIMEOUT_ACTIONresource manager directive.
See "Parallel Queue Timeout".
Cancelling a SQL statement in a session
You can cancel a SQL statement in a session using the
ALTER SYSTEM CANCEL SQLstatement.
A scalable sequence can be used to improve the performance of data load operation in Oracle RAC databases.
See "Making a Sequence Scalable".
Resetting a sequence
RESTARTclause can be used in an
ALTER SEQUENCEstatement to reset a sequence number to a specific value.
See "Altering Sequences".
The Memoptimized Rowstore
The Memoptimized Rowstore enables fast lookup of data for the tables that are mainly queried based on primary key columns. This feature is particularly useful for the applications such as Internet of Things (IoT).
Read-only Oracle home
An Oracle home can be configured in a read-only mode, thus preventing creation or modification of files inside the Oracle home directory
ORACLE_HOME. A read-only Oracle home can be used as a software image that can be shared across multiple database servers. This simplifies patching and mass rollout as only one Oracle home image needs to be updated to distribute a patch to multiple database servers.
Cloning a multitenant pluggable database (PDB) with Oracle Automatic Storage Management (Oracle ASM)
Oracle ASM can be used to create a clone of a PDB.
Proxy resident connection pooling
Proxy resident connection pooling provides improved high availability, security, and performance for database clients. Proxy resident connection pooling uses the Proxy Resident Connection Pool that can be configured using Oracle Connection Manager in Traffic Director Mode.
Integration of Microsoft Active Directory Services with Oracle Database
The Oracle Database can connect directly to Microsoft Active Directory and authenticate and authorize users. This provides a simpler, less complex option than the full featured integration with Oracle Enterprise User Security (EUS) and an Oracle Directory Service.
New nologging clauses for Active Data Guard
Database nologging has been extended to provide better support for use in an Active Data Guard environment without significantly increasing the amount of redo log generation. The following two new nologging modes are introduced as alternatives to the existing nologging mode
STANDBY NOLOGGING FOR DATA AVAILABILITY STANDBY NOLOGGING FOR LOAD PERFORMANCE
New features in DBCA silent mode
Creating a copy of a multitenant container database (CDB)
A copy of a CDB can be created using the
Creating a copy of an Oracle RAC database
A copy of an Oracle RAC database can be created using the
-databaseConfigTypewith the value of
Creating a standby database from an existing database
A standby database can be created from an existing database using the
Verifying hardware and software prerequisites before creating a database
Hardware and software prerequisites for creating a database can be verified by executing the
-executePrereqscommand on the system where the database needs to be created.
Creating a copy of a database template
A copy of a database template can be created using the
Creating a copy of a pluggable database (PDB)
A copy of a PDB can be created using the
-createPDBFromwith the value of
The following are additional changes in the release:
New Oracle Multitenant book
All the Oracle Multitenant topics have been moved from Oracle Database Administrator's Guide to a new book Oracle Multitenant Administrator’s Guide.
New Oracle Sharding book
All the Oracle Sharding topics have been moved from Oracle Database Administrator's Guide to a new book Oracle Database Using Oracle Sharding.
Changes in Oracle Database 12c Release 2 (12.2)
The following are changes in Oracle Database Administrator's Guide for Oracle Database 12c Release 2 (12.2).
The following features are new in this release:
Improvements to online redefinition of tables:
In past releases, tables with
BFILEcolumns could not be redefined online. In Oracle Database 12c Release 2 (12.2), tables with
BFILEcolumns 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
REDEF_TABLEprocedure or the
Optimize the performance of bulk updates to a table with the
EXECUTE_UPDATEprocedure in the
DBMS_REDEFINITIONpackage. Performance is optimized because the updates are not logged in the redo log.
You can query the
V$ONLINE_REDEFview 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
INSERTcould be compressed using Hybrid Columnar Compression.
See "About Table Compression".
Improvements in table move operations
ONLINEkeyword is included in an
ALTER TABLE MOVEstatement, data manipulation language (DML) operations are supported during the move operation. Also, indexes are usable during the move operation when the
ONLINEkeyword is included and the
UPDATE INDEXESclause is included.
SYSRACadministrative 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_TIMEparameter, the new parameter
MAX_TXN_THINK_TIMEfor subprograms in the
DBMS_CONNECTION_POOLpackage 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_INFOview 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_TIMEinitialization 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".
Changes in Oracle Database 12c Release 1 (18.104.22.168)
The following are changes in Oracle Database Administrator's Guide for Oracle Database 12c Release 1 (22.214.171.124).
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.
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.
READobject privilege and
READprivilege on an object enables a user to select from an object without providing the user with any other privileges.
Changes in Oracle Database 12c Release 1 (126.96.36.199)
The following are changes in Oracle Database Administrator's Guide for Oracle Database 12c Release 1 (188.8.131.52).
The following features are new in this release:
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 (184.108.40.206) 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
SYSDBAadministrative 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_TABLEprocedure in the
DBMS_REDEFINITIONpackage 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_timeoutparameter in the
FINISH_REDEF_TABLEprocedure in the
DBMS_REDEFINITIONpackage 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".
COLUMNwith default value for nullable columns
A nullable column is a column created without using the
NULLconstraint. 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_QUEUEfor 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:
IGNORECASEargument of ORAPWD
To support strong authentication, Oracle recommends that you set
IGNORECASEentirely. 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_MAPPINGinitialization parameter is deprecated. It is still supported for backward compatibility.
See Oracle Database Reference for information about the
This view continues to be available for backward compatibility.
See "Specifying Scheduler Job Credentials" for further information.