Why might using the FILTER clause be preferred over using a CASE statement inside an aggregate function for conditional aggregation?

hard📝 Conceptual Q10 of 15

PostgreSQL - Aggregate Functions and GROUP BY

AFILTER improves readability and separates condition from aggregation

BFILTER executes faster because it avoids scanning rows

CCASE statements cannot be used inside aggregate functions

DFILTER automatically indexes the filtered rows

Step-by-Step Solution

Solution:

Step 1: Compare FILTER and CASE usage
FILTER clause clearly separates the condition from the aggregate function, making queries easier to read and maintain.
Step 2: Evaluate other options
FILTER does not avoid scanning rows or create indexes. CASE can be used inside aggregates. Performance differences are usually minimal.
Final Answer:
FILTER improves readability and separates condition from aggregation -> Option A
Quick Check:
FILTER = clearer syntax for conditional aggregation [OK]

Quick Trick: FILTER clause makes conditional aggregates easier to read [OK]

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