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Top 50 Aggregations Interview Questions

The most frequently asked Aggregations questions across all roles and companies, ranked by real interview frequency. Updated daily.

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~17htotal time
1,116companies covered
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1
database optimizationStart here. 3 questions · ~60 min
Optimize a Slow SQL QueryHard
Practice
Recently asked

Rewrite a slow PostgreSQL loan payment query to reduce scanned rows while preserving the required aggregated results.

database optimizationJoinsData WranglingBiz2CreditAmeripriseEEltro Cyberchrome Private
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2
Ranking7 questions · ~140 min
Top Customers by Sales RevenueEasy
Practice
Recently asked

Use GROUP BY and SUM to rank the top 10 customers by total revenue from a single sales table.

RankingGroup ByAggregationsHousecall ProEquifaxXYZ
Top Products by Sales RevenueEasy
Practice
Recently asked

Find the top 10 products by total sales revenue using joins, aggregation, and a CTE.

RankingGroup ByAggregationsRTXiSmile TechnologiesCatalina
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3
Group By5 questions · ~100 min
SQL Duplicate DetectionEasy
Practice
Recently asked

Find duplicate customer profiles by grouping on identifying fields and returning only repeated records.

Group ByHavingAggregationsAdtalem Global EducationUniversity of Southern CaliforniaBlue Cross Blue Shield of Michigan
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4
Joins5 questions · ~100 min
SQL Query for Data ExtractionEasy
Practice
Recently asked

Extract qualifying market observations by venue and price, then return them in chronological order.

JoinsData ManipulationGroup ByEquifaxDPR ConstructionRigUp
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5
Window Functions13 questions · ~260 min
Calculate 30-Day User RetentionHard
Practice
Recently asked

Use CTEs, joins, and date filtering to calculate 30-day retention by signup cohort from login and feature usage data.

Window FunctionsDate FunctionsAggregationsCurefitIndeedTikTok
SQL Window Functions ExperienceMedium
Practice
Recently asked

Use SQL window functions to rank regions by average 2024 yield within each country.

Window FunctionsJoinsData ManipulationErnst & YoungKBRMaximus Tech
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6
Date Functions7 questions · ~140 min
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7
More topics10 questions · ~200 min
Handling Missing DataEasy
Practice
Recently asked

Replace missing sales fields with defined defaults and return a consistently ordered dataset.

missing valuesdata cleaningnull handlingUniversity of MinnesotaThe Home DepotNationwide
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