Retrieving data using the SQL SELECT statement and using single row functions to customize the output

  • /*…*/ and — are used to put comments in an Oracle program.
  • The CREATE TABLE does not end immediately with a semicolon, and a column name cannot start with a numeric value. However, a numeric value can be used in between a column name.
  • Name of a table cannot start with @ special character.
  • Knowing about the GROUP BY clause.

Using sub queries and set operators to solve queries, as well as DDL statements to create and manage tables

Managing objects with data dictionary views, schema objects and data in different time zones

  • The length of a column can be increased even if it contains data. However, the data type of the column cannot be modified if it contains any data.
  • The parameters used to maximize the space in Flash Recovery Area.
  • User error failure refers to a database failure that results due to certain transactions on a database by a user.
  • Flashback Query is used to view and repair historical data, and to view the contents of a table at any specific point in time.
  • UNDO_RETENTION is a parameter in the init.ora initialization parameters file that specifies the time period in seconds for which a system retains undo data for committed transactions.
  • Once the Flashback Versions Query is run to diagnose the erroneous transaction, the Flashback Transaction Query helps in the repair process of the transaction.
  • The correct order of steps that will enable the flashback database are as follows:
    1. Put the database in Archive log mode.
    2. Set up a flash recovery area.
    3. Set the period for the flashback retention target.
    4. Shut down and mount the database.
    5. Enable flashback logging.
    6. Open the database.
  • The overall utilization of the flash recovery area is displayed in megabytes.
  • SQL statement can be used to flashback a database.
  • Take the following steps to enable the Flashback Database:
    1. Ensure that the database is in Archive Log mode.
    2. Setup a flash recovery area.
    3. Set the duration for the flashback retention target.
    4. Shutdown the database.
    5. Mount the database.
    6. Enable flashback logging.
    7. Open the database.
  • The dropped table can be recovered by using Flashback Drop.
  • The flashback database is enabled only in Archive log mode, as it recovers the database to an earlier specific point of time.
  • Flashback Database is used to reverse the changes made to a table.
  • The Perform Recovery: Review screen is used to display the RMAN script that performs the Flashback Database recovery.
  • The portlist.ini file is used to get all the port numbers of the HTTP listeners.
  • RVWR is a background process, which is a part of the Flashback Database Architecture.
  • LGWR is a background process that is a part of Flashback Database Architecture.
  • SELECT oldest_flashback_scn FROM V; is used to retrieve an approximate system change number (SCN) to which a database can be flashed back.

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