3i Infotech Papers: Sample Questions 96 - 98 of 1245

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Question number: 96

» Languages » C & C Plus Plus

Short Answer Question▾

Write in Short

  1. main ()
  2. {
  3.     printf( “%p” main);
  4. }

Explanation

  • In a program

Table shows the program

Table shows the program

  1. main ()
  2. {
  3.     printf( “%p” main);
  4. }

Function names are just addresses (just like array names are addresses).

Here, main () is also a function.

So, the address of function main will be printed.

  • %p in printf specifies that the argument is an address.

  • They are printed as hexadecimal numbers.

  • Some address will be printed

Question number: 97

» Database » MySQL

Essay Question▾

Describe in Detail

When do you get constraint violation? What are the types of constraints?

Explanation

Database returns an error message when a constraint is violated.

Different type of constrains:

  1. Domain Constraints: A Domain constraint deals with one or more columns

  2. Entity Constraints

  3. Referential Integrity Constraints.

  4. Key Constraints

    • Primary Key Constraints
    • Foreign Key Constraints
    • Unique key Constraints

    • Check constraint

    • Default constraint

Question number: 98

» Database » Oracle

MCQ▾

Question

ENQUEUE_RESOURCES parameter information is derived from

Choices

Choice (4) Response

a.

DB_BLOCK_BUFFERS

b.

LOG BUFFER

c.

PROCESS or DDL_LOCKS & DML_LOCKS

d.

DB_BLOCK_SIZE

Answer

c.

Explanation

Define differents types of locks

Define Differents Types of Locks

Define differents types of locks

  • ENQUEUE_RESOURCES parameter information is derived from PROCESS or DDL_LOCKS & DML_LOCKS.

  • ENQUEUE_RESOURCES sets the max resources that can be concurrently locked by the lock manager.

  • DDL_LOCK

  • DDL_LOCK protects the definition of a schema object while the object is referenced in DDL operation.

    DDL_LOCK prevents other DDL operations from referencing or altering the same object.

  • DDL lock requested on an object that already has a DDL lock on it causes the lock to wait.

Three types of DDL locks:

  • Exclusive DDL lock

    • CREATE CLUSTER, DROP/ALTER TABLE, CREATE/ALTER/DROP INDEX, and CREATE/ALTER TABLESPACE require an exclusive lock on the object they are working on.

  • Shared DDL Lock

    • Required on the objects they refer to: audit, noaudit, comment, create.

    • Also create table when the cluster clause isn’t specified.

  • Breakable Parse Locks

    • SQL statement or PL/SQL object in the library cache holds a breakable parse lock for each object it references, until the statement is aged out of the shared pool.

Three types of DDL locks

Three Types of DDL Locks

Three types of DDL locks

  • DML_LOCK:

  • Obtained on a table that is undergoing a DML operation (insert, update, delete).

  • DML_LOCK specifies the maximum number of DML locks for each table modified transaction.

  • Example, three users modifying data in one table would require lock on three entries. If three users are modifying data in two tables, then lock on six entries would be required.