As per the aggregation pipeline optimization concepts, if you have a $sort followed by a $match:

Question

Options

• AProviding these parameters in any order does not impact the performance
• B$sort moves before $match
• CMongoDB does not do any movements by default and will use the order provided
• D$match moves before $sort

• A
  11% (5)
• B
  2% (1)
• C
  7% (3)
• D
  80% (36)

Explanation

MongoDB's aggregation pipeline optimizer automatically moves $match stages before $sort when possible, because filtering documents first reduces the number of records that need to be sorted - sorting is expensive, and doing it on fewer documents is far more efficient.

Why the distractors are wrong:

• A is wrong because order absolutely matters for performance - processing fewer documents earlier is always better.
• B is wrong because moving $sort before $match would mean sorting a larger dataset before filtering, which is the opposite of optimal.
• C is wrong because MongoDB does reorder stages automatically as part of its pipeline optimization phase - it doesn't blindly execute in the order you write.

Memory tip: Think "filter before you sort" - just like you'd sort a stack of papers only after removing the irrelevant ones. MongoDB's optimizer applies the same common sense: $match moves early, $sort stays late.

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