MongoDB Practice Test 7

1. Which of the following provides similar functionality to join?

None of the mentioned

$unwin

$unwindelem

$unwind

2. MongoDB indexes use a _______ data structure.

All of the mentioned

Map

Hash

B-tree

3. ___________ returns either the non-null result of the first expression.

$ElseNull

None of the mentioned

$Null

$ifNull

4. Which of the following is syntax for calculating minimum value?

{ $minimum: <int> }

None of the mentioned

{ $min: <expression>}

{ $minimum: <expression> }

5. ________ returns a set with elements that appear in any of the input sets.

$setIntersection

$setDifference

$setUnion

$setEquals

6. Which of the following ignores non numeric values?

$order

None of the mentioned

$asc

$sum

7. String expressions, with the exception of ________ only have a well-defined behavior for strings of ASCII characters.

None of the mentioned

$concatenation

$setcon

$concat

8. Point out the wrong statement.

None of the mentioned

Set expressions performs set operation on arrays, treating arrays as sets

In addition to the false boolean value, Boolean expression evaluates as false the following: null, 0, and undefined values

Boolean expressions evaluate their argument expressions as booleans and return a boolean as the result

9. MongoDB provides a ________ index type that supports searching for string content in a collection.

string

none of the mentioned

char

text

10. Point out the correct statement.

Expressions cannot include field paths and system variables, literals, expression objects, and expression operators

To avoid parsing ambiguity if the argument is a literal array, you must wrap the literal array in a $lits expression or keep the outer array that designates the argument list

Operator expressions are similar to functions that take arguments

All of the mentioned