3i Infotech Papers: Sample Questions 221 - 222 of 1245

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Question number: 221

» Database » MySQL

Essay Question▾

Describe in Detail

What is “transparent DBMS”


  • It is one, which keeps its Physical Structure hidden from user.

  • A query with respect to DBMS relates to user commands that are used to interact with a database.

  • The query language can be classified into data definition language and data manipulation language.

  • Transparent hides implementation details from the user.

  • For example in a centralized DBMS, data independence is a form of transparency it hides changes in the definition and organization of the data from the user.

  • A DDBMS may provide a various· levels of transparency.

  • They all participate in the same overall objective: to make the use of the distributed database, equivalent to that of a centralized database.

Four types of transparency in DDBMS:

  • Distribution transparency

  • Transaction transparency

  • Performance transparency;

  • DBMS transparency.

Question number: 222

» Database » Oracle



Which of the following is not correct about Cursor?


Choice (4) Response


Cursor holds temporary results


SQL uses implicit Cursors to retrieve rows


Cursor is a named Private SQL area


Cursor is used for retrieving multiple rows




Define cursor and its types

Define Cursor and Its Types

Define cursor and its types


  • Used for retrieving set of rows.

  • Essentially formed by assigning a name to a SELECT statement and manipulate the information within SQL statement.

  • Contains information on a select statement and rows of data accessed by it.

  • Holds more than one row, but it can process only one row at a time.

  • Multiple rows that the cursor holds form the active set.

Two types of cursors:

  • Implicit Cursors

  • Explicit Cursor

Two types of cursors

Two Types of Cursors

Two types of cursors

Implicit Cursors:

  • Automatically generated by oracle when an SQL statement is executed.

  • Created to process the statement when DML statements like INSERT, UPDATE, and DELETE etc. are executed.

Provide some attribute:

  • % FOUND

    • Return value is TRUE if DML statements like INSERT, DELET and Update at least one or more rows and return one or more rows.


    • Return value is TRUE if DML statement like INSERT, DELETE and UPDATE affect no row, or a SELECT INTO statement returns no row.

    • It is a opposite of % FOUND.


    • Returns FALSE for implicit cursor, because the SQL cursor automatically closes after execution.


    • Returns the number of rows affected by DML statement like INSERT, UPDATE, DELETE.

Provide some attribute

Provide Some Attribute

Provide some attribute

Explicit cursors

  • Defined by programmers to gain more control on the context area.

  • Declaration section of the PL/SQL block.

  • Created on a SELECT statement which returns more than one row.


CURSOR cursor_name IS select_statement; ;

Steps of Creating Explicit cursor:

Declare the cursor:

  • Define name of cursor with a name and associated with SELECT statement


    CURSOR name IS

    SELECT statement;

  • Open the cursor:

  • Allocate memory for the cursor to fetch the rows returned by the SQL statement.


    OPEN cursor_name;

  • Fetch the cursor:

  • Access one row at a time. We can fetch row from the above-opened cursor.


    FETCH cursor_name INTO variable_list;

  • Close the cursor:

  • Release the allocated memory


Close cursor_name;