My database OCP

The function of listening is to establish the data connection between the client computer and the central database computer. Once the connection is made without any effect on the two, the user on the connected client can do any operation and query, even if the listener has been shut down or destroyed, but the new remote connection can no longer connect to the database after the stop.

The purpose of the Undo table space:

1. Rolling back a transaction explicitly with a ROLLBACK statement
2. Rolling back a transaction implicitly (for example, through recovery of a failed transaction)
3. Reconstructing a read-consistent image of data
4. Recovering from logical corruptions.

1) ROLLBACK TRANSACTION: Rollback
2) Read consistency: The data block that is doing the DML operation, before the transaction ends, the other user reads the data in the undo before
Mirror
3) Instance recovery: Instance recover (undo-------->rollback)
4) Flash Back technology: Flashback query, Flashback table, etc.

Because the database is abnormally stopped, changes in the time that the database was issued the last checkpoint to the database exception stop were recorded in the Redo log file and not written to the number file, so in the process of database instance recovery, all the redo log files after the last checkpoint are required. Write the corresponding changes to the data file.

Adding a non-null constraint is using modify instead of add CONSTRAINT

OK, can you use data Recovery Advisor to recover from the two situations below?

the One cannot start up the database (because required database files is missing, inconsistent, or corrupted) a nd the one when file corruptions is discovered during run time.  

A. The database files are corrupted when the database is open

D. The database is not opening because the required database files are missing

Delay integrity constraints.

http://bbs.cqsztech.com/forum.php?mod=viewthread&tid=516

Role:

http://bbs.cqsztech.com/forum.php?mod=viewthread&tid=509

SQL tuning.

http://bbs.cqsztech.com/forum.php?mod=viewthread&tid=518

Which of the two files in the database can be automatically backed up by automatic backup in Rman?

The automatic backup of the control file occurs independently of any backup of the current control file explicitly request Ed as part of your backup command. If you enable control file Autobackups, then RMAN automatically backs up the control file and the current server parameter File

Sql*loader

http://bbs.cqsztech.com/forum.php?mod=viewthread&tid=521

In the following case, even if the parameter undo_retention specifies a value, it may be ignored?

For Fixed-size undo tablespaces, the system automatically tunes for the best possible undo retention period on the basis O F Undo tablespace size and usage history; It ignores undo_retention unless RETENTION guarantee is enabled.

you want the employee information contained in the flat file to be accessed as part of the employees, so you plan to add a column to the Employees table,
      This new column will you use that data type?

Clob uses char to save data.
blobs are used to store data in binary.
BFILE data is stored in the operating system files, not in the database.
LING Raw This data type is used to store binary data that is not interpreted by Oracle.

My database OCP