Tag: databases

Questions Related to databases

What are the Capabilities of SELECT Statement?
technology databases

  1. Selection

  2. Projection

  3. Joining

  4. None of these

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Correct Option: A,B,C

To join n tables together, you need a minimum of ________ join conditions
technology databases

  1. N-2

  2. N

  3. N-1

  4. None of these

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Correct Option: C

Equijoins are also called______ or __________
technology databases

  1. simple joins

  2. outer joins

  3. inner joins

  4. inner and outer joins

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Correct Option: A,C

How many columns are presented after executing this query: SELECT address1||','||address2||','||address2 "Adress" FROM employee;
technology databases

  1. 1

  2. 2

  3. 3

  4. 0

  5. 4

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Correct Option: A

Which Oracle access method is the fastest way for Oracle to retrieve a single row?
technology databases

  1. Primary key access

  2. Access via unique index

  3. Table access by ROWID

  4. Full table scan

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Correct Option: C

Which of the following can be a valid column name?
technology databases

  1. Column

  2. 1966_Invoices

  3. Catch_#22

  4. #Invoices

  5. None of the above

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Correct Option: C

Which command will delete all data from a table and will not write to the rollback segment?
technology databases

  1. drop

  2. delete

  3. cascade

  4. truncate

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Correct Option: D

Which character function can be used to return a specified portion of a character string?
technology databases

  1. INSTR

  2. SUBSTRING

  3. SUBSTR

  4. POS

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Correct Option: C

The primary key on table EMP is the EMPNO column. Which of the following statements will not use the associated index on EMPNO?
technology databases

  1. select * from EMP where nvl(EMPNO, '00000') = '59384';

  2. select * from EMP where EMPNO = '59384';

  3. select EMPNO, LASTNAME from EMP where EMPNO = '59384';

  4. select 1 from EMP where EMPNO = '59834';

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Correct Option: A

When a user creates an object without a TABLESPACE clause, where will Oracle store the segment?
technology databases

  1. System tablespace

  2. Users tablespace

  3. Default tablespace for the user

  4. Oracle will give an error

  5. Undefined

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Correct Option: C