See "Using Operating System Authentication" for more information. Typically, all users with the CREATE SESSION system privilege can connect to an open database. ORACLE. For example, if instances 1, 2, and 3 are running, and you issue an ALTER SYSTEM SUSPEND statement from instance 1, then you can issue a RESUME statement from instance 1, 2, or 3 with the same effect.
Doing so makes the database available for any valid user to connect to and perform typical data access operations. In this case oracle will try to recover the database with automatic crash recovery, if that also fails then oracle will ask the dba to manually recover the datbase using media recovery methods.
Starting Up with SQL*Plus with a Nondefault Server Parameter File, Starting Up with SRVCTL with a Nondefault Server Parameter File. The use of the command is as follows. QUIESCED: Quiesced; no non-DBA sessions are active or allowed. Oracle reads the parameter files (spfile or pfile) in this step. Use one of the following commands: You can start an instance and mount a database without opening it, allowing you to perform specific maintenance operations. Sql> alter system disable restricted session; A DBA must log in to the database to issue the statement that specifically unquiesces the database. For SRVCTL, if the -stopoption option is omitted, the shutdown operation proceeds according to the stop options stored in the Oracle Restart configuration for the database. Learn how your comment data is processed. Performing full database recovery.
Other options exist, and these are also discussed in this section.
To the user, it appears as if the login is hung. See Chapter 4, "Configuring Automatic Restart of an Oracle Database" for details. For example, create a text initialization parameter file /u01/oracle/dbs/spf_init.ora that contains only the following parameter: Start up the instance pointing to this initialization parameter file. A concurrent user who attempts to access the table after it was dropped, but before import, would not have an accurate view of the situation. For example: Now you are connected to the database and ready to start up an instance of your database. Or we can mount a closed database directly as follows. The instance is created by reading all the values from a file known as init.ora parameter file. please follow usonFacebook|Twitter Control is not returned to the session that initiates a database shutdown until shutdown is complete. Thank you for giving your valuable time to read the above information. After ORA-01013 occurs, you must consider the instance to be in an unpredictable state. You can also use Recovery Manager (RMAN) to execute STARTUP and SHUTDOWN commands. Before the database is shut down, the database waits for all currently connected users to disconnect from the database. The next startup of the database will require automatic instance recovery procedures. (If long uncommitted transactions exist, this method of shutdown might not complete quickly, despite its name.). Procedures for starting and stopping remote instances vary widely depending on communication protocol and operating system. Cloud Control enables you to perform the functions discussed in this book using a GUI interface, rather than command line operations. You cannot compile or recompile PL/SQL stored procedures on a read-only database. Oracle Real Application Clusters Administration and Deployment Guide, Oracle Database Backup and Recovery Reference, Initialization Files and Oracle Automatic Storage Management, Oracle Database Backup and Recovery User's Guide, Chapter 4, "Configuring Automatic Restart of an Oracle Database", "Starting and Stopping Components Managed by Oracle Restart", Chapter 2, "Creating and Configuring an Oracle Database", "SRVCTL Command Reference for Oracle Restart", "Submitting Commands and SQL to the Database", Chapter 12, "Managing Archived Redo Log Files", "Starting an Instance and Mounting a Database", "Creating a Locally Managed Temporary Tablespace", "Restricting Access to an Instance at Startup", Chapter 27, "Managing Resources with Oracle Database Resource Manager". If all events blocking the shutdown do not occur within one hour, the shutdown operation aborts with the following message: ORA-01013: user requested cancel of current operation. These actions include: Actions that fail if concurrent user transactions access the same object--for example, changing the schema of a database table or adding a column to an existing table where a no-wait lock is required. MOUNTStart the instance and mount the database, but leave it closed. The use of the command is as follows. To start up with SQL*Plus with a nondefault server parameter file: Create a one-line text initialization parameter file that contains only the SPFILE parameter. An application writes database objects when it manipulates a database sequence. To place an already running instance in restricted mode, use the SQL statement ALTER SYSTEM with the ENABLE RESTRICTED SESSION clause. Open state: Incase any of the physical files is missing then sanity check will fail. The following statement opens a database in read-only mode: You can also open a database in read/write mode as follows: An application must not write database objects while executing against a read-only database.
See "SRVCTL Command Reference for Oracle Restart" for more information. Cloud Control combines a GUI console, agents, common services, and tools to provide an integrated and comprehensive systems management platform for managing Oracle products. Details are provided in the following sections: Shutting Down with the Transactional Mode. You cannot invoke a remote procedure (even a read-only remote procedure) from a read-only database if the remote procedure has never been called on the database. You can use Cloud Control to administer your database, including starting it up and shutting it down.
Any uncommitted transactions are rolled back. Further, when the instance is in restricted mode, a database administrator cannot access the instance remotely through an Oracle Net listener, but can only access the instance locally from the system that the instance is running on. Initialization Files and Oracle Automatic Storage ManagementA database that uses Oracle Automatic Storage Management (Oracle ASM) usually has a nondefault SPFILE. A service automatically starts upon manual database startup only if the management policy of the service is AUTOMATIC and if one of its assigned roles matches the current role of the database. When Oracle Restart is not in use, you can shut down a database instance with SQL*Plus by connecting as SYSOPER, SYSDBA, SYSBACKUP, or SYSDG and issuing the SHUTDOWN command.
However, should such a need arise, both SRVCTL (with Oracle Restart) and SQL*Plus provide ways to do so. If your database is being managed by Oracle Restart, the recommended way to start the database is with SRVCTL. This can cause client computers to lose work. We can open an already mounted database by below command. Startup and shutdown modes oracle database, Startup and shutdown modes of Oracle database, Oracle database startup modes activity guide. When you want to perform a planned shutdown of an instance while allowing active transactions to complete first, use one of the following commands: Transactional database shutdown proceeds with the following conditions: After all transactions have completed, any client still connected to the instance is disconnected. For example, if the database stores data in Oracle Automatic Storage Management (Oracle ASM) disk groups, ensure that the Oracle ASM instance is running and the required disk groups are mounted. This is true even if you execute a generic SELECT statement on the first database link and the transaction is currently read-only.
Oracle offers us 5 different methods for shutting down the database. In this article, I will explain the startup and shutdown modes of Oracle database. This stage is only used when first creating a database or when it is necessary to recreate a databases control files. Shut abort is used when we have a loss of files at the o/s level. This mode allows any valid user to connect to the database and perform data access operations. The following command starts an instance and mounts the database, but leaves the database closed: You can start an instance, and optionally mount and open a database, in restricted mode so that the instance is available only to administrative personnel (not general database users). Current SQL statements are immediately terminated. If your application calls any of these functions and procedures, or if it performs any of the preceding operations, your application writes database objects and hence is not read-only.
The database implicitly rolls back active transactions and disconnects all connected users. 1) The mount state is used to recover a database that has crashed due to media failure.
It only waits for the current fetch to finish. When Oracle Restart is not in use, you can start up a database instance with SQL*Plus, Recovery Manager, or Oracle Enterprise Manager Cloud Control (Cloud Control). The database looks for these files in a default location. Otherwise, the query will fail. When we restart the db after a shut abort then oracle smon will have to perform crash recovery. These are described later in this section. If it will take too long to shutdown the database in a consistent manner, this method can be used. To start an instance, the database must read instance configuration parameters (the initialization parameters) from either a server parameter file (SPFILE) or a text initialization parameter file (PFILE).
Nomount Mode: The instance and background processes start when we open the Oracle database in Nomount mode. Lastly, I will explain this command.
If all the scns in the dbfs are matched with the scn in the controlfile then the db can be opened for use. 2) Re-create a controlfile for an existing database. Pleasesubscribeto our newsletter. When Oracle Restart is not in use, you use the SQL*Plus STARTUP command to start up an Oracle Database instance. Mehmet Salih DEVEC Start SQL*Plus without connecting to the database: Connect to Oracle Database as SYSOPER, SYSDBA, SYSBACKUP, or SYSDG. A MANUAL setting does not prevent Oracle Restart from monitoring the service when it is running and restarting it if a failure occurs.
Shutdown modes that wait for users to disconnect or for transactions to complete have a limit on the amount of time that they wait. The quiesced state lets administrators perform actions that cannot safely be done otherwise. See Chapter 27, "Managing Resources with Oracle Database Resource Manager" for more information about the Database Resource Manager. Occasionally you might want to put a database in a state that allows only DBA transactions, queries, fetches, or PL/SQL statements. The suspend/resume feature is useful in systems that allow you to mirror a disk or file and then split the mirror, providing an alternative backup and restore solution.
OPEN RECOVERStart the instance and have complete media recovery begin immediately. With SQL*Plus you can use the PFILE clause to start an instance with a nondefault server parameter file. If possible, perform this type of shutdown only in the following situations: The database or one of its applications is functioning irregularly and none of the other types of shutdown works. The suspended state lets you back up a database without I/O interference. When we try to close the database with this method, Oracle waits all users connected to the database to finish their jobs and close their sessions. This chapter contains the following topics: When you start up a database, you create an instance of that database and you determine the state of the database. You may want to do this in order to restrict access for maintenance reasons or to make the database read only. We can mount a database in Nomount mode as follows. This limitation applies to remote procedure calls in anonymous PL/SQL blocks and in SQL statements. For example, an application writes database objects when it inserts, deletes, updates, or merges rows in a database table, including a global temporary table. The database implicitly disconnects all connected users. If you (or the Database Configuration Assistant) created a server parameter file, but you want to override it with a text initialization parameter file, you can do so with SQL*Plus, specifying the PFILE clause of the STARTUP command to identify the initialization parameter file: Nondefault Server Parameter FilesA nondefault server parameter file (SPFILE) is an SPFILE that is in a location other than the default location. All transactions are suddenly stopped and the database is closed inconsistently. You experience problems when starting a database instance. The following command starts an instance, reads the initialization parameters from the default location, and then mounts and opens the database. From nomount the dba can take the database to mount state. For both dedicated and shared server connections, all non-DBA logins after this statement is issued are queued by the Database Resource Manager, and are not allowed to proceed. You can then restart the instance. The procedures for performing this task are specific to each operating system. Some shutdown modes wait for certain events to occur (such as transactions completing or users disconnecting) before actually bringing down the database. This can be done in unrestricted mode, allowing access to all users, or in restricted mode, allowing access for database administrators only. In the mount state oracle will open the controlfile.
A common scn number will be updated to controlfiles and datafiles before the database shutsdown.
Database and redo buffers are NOT written to disk. shutdown modes include shutdown abort, shutdown transactional, shutdown normal, shutdown immediate. The use of the command is as follows. Some restrictions apply when combining clauses of the STARTUP command or combining startup options for the srvctl start database command. For example, If a user issues a SQL query in an attempt to force an inactive session to become active, the query will appear to be hung.
Also, read Oracle database startup modes activity guide. In this case, the alert log shows the message "Shutting down instance (abort)" followed by "Starting ORACLE instance (normal).". Pleasecontact us for any information/suggestion/feedback. In the platform-specific default location, Oracle Database locates your initialization parameter file by examining file names in the following order: The first two files are SPFILEs and the third is a text initialization parameter file. See "srvctl add service" and "srvctl modify service" for the syntax for setting the management policy of and Data Guard roles for a service. This is a serious restriction, especially for systems requiring 24 x 7 availability. The V$INSTANCE view is queried to confirm database status. An example of such a setting is the server parameter file location. But incase of a shut abort oracle does not get the chance to write the common scn thus when we restart the database then oracle will find that the scn does not match for the data files and the control file. Thus oracle will call smon to perform crash recovery or instance recovery. FORCEForce the instance to start after a startup or shutdown problem. No inactive sessions are allowed to become active. Use the ALTER SYSTEM RESUME statement to resume normal database operations. This is the LEAST favored option because the next startup will require instance recovery and you CANNOT backup a database that has been shut down with the ABORT option. Ensure that any Oracle components on which the database depends are started. When Oracle Restart is installed and configured for your database, Oracle recommends that you use SRVCTL to start the database. At this point, the instance shuts down just as it would when a SHUTDOWN IMMEDIATE statement is submitted. There is a one-hour timeout period for these events. A closed Oracle database opens in 3 stages. When this command is issued then oracle will not allow any new connections/sessions to the database and will wait for the users to commit/rollback their open transactions after which oracle will shut the database. Later, use the ALTER SYSTEM statement to disable the RESTRICTED SESSION feature: If you open the database in nonrestricted mode and later find that you must restrict access, you can use the ALTER SYSTEM statement to do so, as described in "Restricting Access to an Open Database". If you want to be updated with all our articles. where db_unique_name matches the DB_UNIQUE_NAME initialization parameter. *the mount state is used by the dba to perform recovery Only database administrators should have the RESTRICTED SESSION system privilege. Also, read The activity post for the Startup and shutdown modes of Oracle database. If you intend to use operating system authentication, log in to the database host computer as a member of the OSDBA group. Table 2-3 lists PFILE and SPFILE default names and locations. For more information, see "Using Force Full Database Caching Mode". When this command is executed, oracle rollbacks uncommitted transactions and executes the shutdown procedures. For details, see "Submitting Commands and SQL to the Database". You can join it with V$SESSION to get more information about the session, as shown in the following example: See Oracle Database Reference for details on these view. When your database is managed by Oracle Restart, you can configure startup options for each individual database service (service). IF the scn is the same then that file can be opened successfully, this way oracle will compare all the scns for all the files with the scn in the controlfile, only when all scns are matched with controlfile scn then only can the database be opened. The SGA memory allocation is released and background processes terminate. Although this method is not preferred, it is sometimes very necessary. Sql> select database_status from v$instance; Sql> select database_status from v$instance; Quiesce a database gives us the opportunity to put our database in a single user mode without shutting down the database. We can start a closed database directly in Open mode as follows. Based on the values from this file oracle will allocate the sga in the RAM and start the background processes.
If DBCA created the SPFILE in an Oracle Automatic Storage Management disk group, the database searches for the SPFILE in the disk group. If subsequent SHUTDOWN commands continue to fail, you must submit a SHUTDOWN ABORT command to bring down the instance. For example, you are doing a very critical operation and time is very important for you and you need to close or restart the database. You must shut down the database instantaneously (for example, if you know a power shutdown is going to occur in one minute). This happens very quickly. When this command is issued then oracle will not allow any new connections/sessions to the database and will forcefully disconnect the existing connected users from the database and rollback all uncommited transactions and shut the database. Uncommitted transactions are not rolled back. No connected client can start a new transaction. In open state oracle checks for the existence of datafiles and redo log files and it also performs a check for synchronization of SCN number. For more information about the server parameter file for an Oracle Real Application Clusters environment, see Oracle Real Application Clusters Administration and Deployment Guide. Ensure that environment variables are set so that you connect to the desired Oracle instance. When ever we are shutting a database in a normal way then before shutting the oracle database, oracle will write a common scn to the file headers of the datafiles and to the controlfile. In unusual circumstances, you might experience problems when attempting to start a database instance. The remainder of this section describes using SQL*Plus to start up a database instance. If you set the management policy for a service to AUTOMATIC (the default), the service starts automatically when you start the database with SRVCTL. The Instance is terminated without closing files.
If your database is being managed by Oracle Restart, the recommended way to shut down the database is with the srvctl stop database command. The SUSPEND and RESUME commands can be issued from different instances.
"Starting and Stopping Components Managed by Oracle Restart" for instructions for starting a database that is managed by Oracle Restart. February 26, 2019 OPENStart the instance, and mount and open the database. To shut down a database in normal situations, use one of these commands: The NORMAL clause of the SQL*Plus SHUTDOWN command is optional because this is the default shutdown method. If you interrupt the request to quiesce the database, or if your session terminates abnormally before all active sessions are quiesced, then Oracle Database automatically reverses any partial effects of the statement. This does not allow access to the database and usually would be done only for database creation or the re-creation of control files. To open a mounted database, use the ALTER DATABASE SQL statement with the OPEN clause: After executing this statement, any valid Oracle Database user with the CREATE SESSION system privilege can connect to the database. There after it will save all the commited transactions and then shut the database. Without the ability to quiesce the database, you would need to shut down the database and reopen it in restricted mode. An application writes database objects when it locks rows, when it runs EXPLAIN PLAN, or when it executes DDL. This mode has been introduced from oracle 10g onwards. The database will not close even if a single session is open. Open Mode: In this mode, the database opens normally and can be accessed by other users. Also, it is preferable to start the Oracle Net listener before starting the database. Using SQL*Plus in this way is the only method described in detail in this book.
When the database is suspended all preexisting I/O operations are allowed to complete and any new database accesses are placed in a queued state. *the nomount state is used by the dba to create a new oracle database. You can alter the availability of a database. For more information, see Oracle Database Backup and Recovery User's Guide. The use of the command is as follows.
Clients are disconnected as soon as the current transaction ends. We can bring a database in Mount mode to Open mode as follows. The best summarizing image is as follows. Sql> alter system suspend; Environment variables stored in the Oracle Restart configuration for the database are set before starting the instance. In either case, you can start an instance in various modes: NOMOUNTStart the instance without mounting a database. Therefore, the preceding method also provides a means for a client system to start a database that uses an SPFILE.
Such a state is referred to as a quiesced state, in the sense that no ongoing non-DBA transactions, queries, fetches, or PL/SQL statements are running in the system. Shutdown abort: This method is like unplugging the database.
When the client system reads the initialization parameter file containing the SPFILE parameter, it passes the value to the server where the specified SPFILE is read.
Shutdown proceeds when all transactions are finished. The following sections explain how to alter the availability of a database: When you perform specific administrative operations, the database must be started and mounted to an instance, but closed. You can start a SQL*Plus session, connect to Oracle Database with administrator privileges, and then issue the STARTUP command.