---
title: "Short note: Warehouse and query manager"
subject: "Data Mining"
chapter: 1
key: "semester_7/data_mining:roles-warehouse-query-manager"
source: https://www.bctengineer.com/q/semester_7/data_mining/roles-warehouse-query-manager
site: BCT Engineering
---

# Short note: Warehouse and query manager

Data Mining · Chapter 1: Introduction

- Asked in: 2066 Bhadra, 3 marks
- Video: [Process Managers in Data Warehousing | Lecture #16 | Data Warehouse Tutorial](https://www.youtube.com/watch?v=d_B5FvtDi5s) — AmpCode
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_7/data_mining/roles-warehouse-query-manager
- Whole chapter: https://www.bctengineer.com/md/semester_7/data_mining/chapter-1

## Question

Write a short note on the roles of warehouse manager and query manager in DW.

## Short answer

The warehouse manager checks consistency, transforms and merges data, creates indexes and views, generates aggregations, archives, backs up, and updates metadata. The query manager directs queries to the right tables, schedules and balances them, generates query profiles, controls access, and returns results. Together they prepare and serve warehouse data.

## Answer

#### Warehouse manager
The warehouse manager is the component that manages the data once it is in the warehouse. Its roles:
- Analyse data for consistency and referential integrity.
- Transform and merge source data from temporary storage into the warehouse tables.
- Create indexes and views on base tables.
- Generate denormalisations and aggregations (summary tables).
- Archive data and take backups.
- Update metadata.

#### Query manager
The query manager handles all user queries and directs them to the right data. Its roles:
- Direct each query to the proper table (detailed or summary).
- Schedule and balance the execution of queries.
- Generate query profiles so the warehouse manager knows which aggregations to build.
- Control access and security, and return results to the user tool.
- Maintain the query log and statistics for tuning.

Together, the warehouse manager prepares data and the query manager serves it.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. Which task belongs to the warehouse manager?
   A. Routing queries to the right table
   B. Controlling user query scheduling
   C. Creating indexes, views and aggregations and taking backups
   D. Generating query profiles
   Answer: C. The warehouse manager manages data inside the warehouse: indexes, aggregates, archive and backup. (Key point: Warehouse manager role)

2. Which task belongs to the query manager?
   A. Merging source data
   B. Directing queries to detailed or summary tables and scheduling them
   C. Archiving old data
   D. Updating metadata after load
   Answer: B. The query manager routes and schedules user queries. (Key point: Query manager role)

3. Why does the query manager generate query profiles?
   A. To back up metadata
   B. To delete unused users
   C. So the warehouse manager knows which aggregations to build
   D. To clean duplicates
   Answer: C. Profiles show which queries are common, guiding which summaries to build. (Key point: Query profiles)

## Related in Data Mining

- [Role of warehouse manager](https://www.bctengineer.com/question.md?key=semester_7%2Fdata_mining%3Awarehouse-manager-role) — Data Mining, chapter 1
- [DW characteristics vs operational database](https://www.bctengineer.com/question.md?key=semester_7%2Fdata_mining%3Adw-characteristics-vs-operational) — Data Mining, chapter 1
- [Data mining vs DW and applications](https://www.bctengineer.com/question.md?key=semester_7%2Fdata_mining%3Adm-vs-dw-applications) — Data Mining, chapter 1
- [Importance, uses and characteristics of DW](https://www.bctengineer.com/question.md?key=semester_7%2Fdata_mining%3Adw-importance-uses-characteristics) — Data Mining, chapter 1
- [Need of DW and DM in government, medical, military](https://www.bctengineer.com/question.md?key=semester_7%2Fdata_mining%3Adw-necessity-gov-medical-military) — Data Mining, chapter 1
- [RDBMS vs DW database; DW terms](https://www.bctengineer.com/question.md?key=semester_7%2Fdata_mining%3Ardbms-vs-dw-terms) — Data Mining, chapter 1