Tag: databases

Questions Related to databases

Which is NOT the single-row functions??
technology databases

  1. sinh()

  2. to_number()

  3. sqrt()

  4. round()

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Correct Option: B

What is the default character for specifying substitution variables in select statements?
technology databases

  1. Ellipses

  2. Quotation marks

  3. Ampersand

  4. Asterisk

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Correct Option: C

You are managing constraints on a table in Oracle. Which of the following choices correctly identifies the limitations on check constraints?
technology databases

  1. Values must be obtained from a lookup table.

  2. Values must be part of a fixed set defined by create or alter table.

  3. Values must include reserved words, such as SYSDATE and USER.

  4. The column cannot contain a NULL value.

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Correct Option: B

The transaction control that prevents more than one user from updating data in a table is which of the following?
technology databases

  1. lock

  2. commit

  3. rollback

  4. savepoint

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Correct Option: A

You are using SQL operations in Oracle. All of the following DATE functions return a DATE datatype except one. Which one is it?
technology databases

  1. NEW_TIME

  2. LAST_DAY

  3. ADD_MONTHS

  4. MONTHS_BETWEEN

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Correct Option: D

Which operator will be evaluated first in the following SELECT statement?
technology databases

  1. +

  2. *

  3. /

  4. _

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Correct Option: B

Which function can return a non-NULL value if passed a NULL argument?
technology databases

  1. LENGTH

  2. CONCAT

  3. INSTR

  4. NULLIF

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Correct Option: B

Which datatype stores data outside Oracle Database?
technology databases

  1. UROWID

  2. BLOB

  3. NCLOB

  4. BFILE

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Correct Option: D

Which of the following statements are true?
technology databases

  1. Primary key constraints allow NULL values in the columns.

  2. Unique key constraints allow NULL values in the columns.

  3. Primary key constraints do not allow NULL values in the columns.

  4. A nonunique index cannot be used to enforce primary key constraints.

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Correct Option: B,C

At a minimum, how many join conditions should be there to avoid a Cartesian join if there are three tables in the FROM clause?
technology databases

  1. 1

  2. 2

  3. 3

  4. There is no minimum.

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Correct Option: B