PCS Infotech Papers: Sample Questions 9 - 10 of 25

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Question number: 9

» Database » Oracle

True-False▾

Question

Is the Following Statement True or False?

ROWID is a pseudocolumn of every oracle table

Answer

FALSE

Explanation

  • ROWID pseudocolumn returns the address of the row - A ROWID value uniquely identifies a row within a cluster.

  • Behaves like a table column, is not actually stored in the table.

  • Row numbers and row descriptions automatically stored and is directly accessible.

  • Information in pseudocolumn can be received in queries.

  • Rows in different tables that are stored together in the same cluster the same rowid.

  • Provides quick access to a row- fastest possible access to a row of a given table.

Question number: 10

» Database » MySQL

True-False▾

Question

Is the Following Statement True or False?

In SQL SGA area the parser tree and exceptions are stored which are used for multiple applications.

Answer

FALSE

Explanation

  • SGA is used to store incoming data and control the information.

  • Area of memory allocated when an oracle instance starts up.

  • Size and function are controlled by initialization parameters.

  • Contains shared server and background processes.

Common components in STA:

  • Data buffer cache:

    • Cache data and index block for faster access.

  • Shared pool:

    • Cache parsed SQL and PL/SQL statements.

  • Dictionary cache:

    • Information about data dictionary objects.

  • Redo Log Buffer:

    • Committed transactions that are not written to the redo log files.

  • JAVA pool:

    • Caches parsed java program

  • Streams pool:

    • Caches oracle streams objects.

  • Large pool:

    • Used for backup.