ORACLE9I 1Z0-032认证知识点总结摘要（二）

RECOVERY_PARALLELISM specifies the number of processes to participate in instance or crash recovery. A value of 0 or 1 indicates that recovery is to be performed serially by one process. You can enable parallel recovery to tune the cache recovery phase. During thread or media recovery, the redo log is read, and redo blocks that are to be applied are parsed out. These blocks are subsequently distributed evenly to all recovery processes to be read into the buffer cache. Crash and instance recovery of datafiles on different disk drives are good candidates for parallel recovery.

 

You can use RMAN with Block Media Recovery to restore and recover only those blocks. It is not required to set the individual data file offline. BMR enables you to back up specific blocks in a datafile without taking the database offline. The default backup method is datafile media recovery. You use the new BLOCKRECOVER statement to perform BMR.

 

The LOG_ARCHIVE_DEST_n initialization parameter control the data availability mode of a Data Guard standby database with three attributes: SYNC or ASYNC for the network transmission mode, LGWR or ARCH to identify the primary database process responsible for sending redo information to the standby and AFFIRM or NOAFFIRM to control whether log archiving disk write operations are to be performed synchronously or asynchronously.

 

Oracle9i has introduced a new package called DBMS_METADATE that enables you to retrieve all the attributes of the database object from the data dictionary with one innovation. Also you can use other methods, available in earlier versions of Oracle for documenting the objects in an existing database: query the various tables in the data dictionary to obtain information about an object, export/import utilities.

 

You will start the listener with default name LISTENER using this command. The LOCAL_LISTENER parameter must be configured in the database initialization parameter file to enable the PMON process to register the service information with the non-default loal listener. LOCAL_LISTENER specifies a network name that resolves to an address or address list of Oracle Net local listeners. The address or address list is specified in the TNSNAMES. ORA file or other address repository as configured for your system.

 

Oracle Net provides the following basic network functionality such as Connect and Disconnect operations, data operations and exception operations. Oracle Net includes Oracle Net Foundation Layer and Oracle Protocol Suppot. They reside on the top of the Network Protocol layer. Oracle Net must be on both the client and the server for peer-to-peer communication to occur.

 

It is possible to rebuild reverse key, function-based, key-compressed indexes on regular tables and on IOT( including secondary indexes).

 

Oracle9i simplifies the process of converting a LONG or LONG RAW column into a CLOB or BLOB column respectively. You use the ALTER TABLE… MODIFY statement to change a LONG or LONG RAW column into a CLOB or BLOB column respectively.

 

By default, the PMON process registers service information with its local listener on the default local address of TCP/IP, port 1521. As long as the listener configuration is synchronized with the database configuration, PMON can register service information with a nondefault local listener or a remote listener on another node. Synchronization is simply a matter of specifying the protocol address of the listener in the listener.ora file and the location of the listener in the initialization parameter file.

 

The RMAN BACKUP command using the DELETE INPUT option can be used with data files and backup sets. The BACKUP … DELETE INPUT command can delete archived redo logs. Datafile copies, and backup sets after backing them up . This functionality is especially useful when backing up archived logs on disk to tape. RMAN backs up one and only one copy of each log sequence number, and then deletes the file that it backs up.

 

The RESYNC CATALOG command performs a full resynchronization of the recovery catalog. Resynchronizations can be full or partial. When full, RMAN updates all changed records for the physical schema: datafiles, tablespaces, redo threads, and online redo logs. If the database is open, RMAN also obtains data about rollback segments. When partial, RMAN reads the current control file to update data, but does not resynchronize metadata about the physical schema or rollback segments.

 

Oracle Shared Server required Oracle Net Service even if the client and shared server processes reside on the same machine. To use shared servers, a user process must connect through Oracle Net Services or SQL*Net version 2, even if the process runs on the same machines as the Oracle instance.

 

Oracle Net Configuration Assistant is provided primarily to configure basic network components during installation, including: listener names and protocol addresses, naming methods the client will use to resolve connect identifiers to connect descriptors, net service names in a tnsnames.ora file, directory server usage. When you use the Oracle Net Configuration Assistant to specify the naming method sqlnet.ora file is updated.