---
title: "Virtual warehouse, data mart, enterprise warehouse"
subject: "Data Mining"
chapter: 1
key: "semester_7/data_mining:virtual-data-mart-enterprise-warehouse"
source: https://www.bctengineer.com/q/semester_7/data_mining/virtual-data-mart-enterprise-warehouse
site: BCT Engineering
---

# Virtual warehouse, data mart, enterprise warehouse

Data Mining · Chapter 1: Introduction

- Asked in: year not given
- Video: [Difference Between Data Warehouse, Data Mart & Data Lake](https://www.youtube.com/watch?v=jnfMA2YVRtw) — Gate Smashers
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_7/data_mining/virtual-data-mart-enterprise-warehouse
- Whole chapter: https://www.bctengineer.com/md/semester_7/data_mining/chapter-1

## Question

What are Virtual Warehouse, Data Mart and Enterprise Warehouse? Explain.

## Short answer

A virtual warehouse is a set of views over operational databases with little or no separate storage and no historical data. A data mart is a subset of warehouse data for one department, built faster and cheaper. An enterprise warehouse integrates all subject areas with detailed and summary data for the whole organization.

## Answer

#### Virtual warehouse
A set of **views** defined over the operational databases, with no separate storage of the warehouse data (only some summary views may be materialised). It is easy and cheap to build, but queries run on operational servers (slowing them), and historical data is not kept.
Example: a bank defines a view "monthly deposits per branch" on its transaction tables.

#### Data mart
A **subset of the warehouse** for one department or subject, such as marketing or sales. It is smaller, cheaper and faster to build, giving faster queries. It can be dependent (from an enterprise warehouse) or independent (from sources).
Example: a telecom's "prepaid customers" mart.

#### Enterprise warehouse
Holds **all subject areas** of the whole organisation, with integrated, detailed and summary data from all sources. It needs large investment and long development, and is the single source of truth for decision making.
Example: the central warehouse of a bank combining deposits, loans, cards and HR data.

| Point | Virtual | Data mart | Enterprise |
|---|---|---|---|
| Scope | Selected views | One subject | Whole organisation |
| Storage | None / little | Own | Own, very large |
| Build time | Short | Weeks to months | Months to years |
| History | No | Yes | Yes |

## Check yourself

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

1. A drawback of a virtual warehouse is:
   A. Very high cost
   B. Queries run on operational servers, slowing them, and no historical data is kept
   C. Takes years to build
   D. Cannot use views
   Answer: B. It has no separate storage. (Key point: Virtual warehouse drawback)

2. A data mart is:
   A. A subset for one department or subject, cheaper and faster to build
   B. The whole organisation's data
   C. A set of views only
   D. An ETL tool
   Answer: A. Examples: marketing or prepaid-customers mart. (Key point: Data mart scope)

3. The enterprise warehouse is:
   A. Quick to build
   B. Holds all subject areas as a single source of truth, but needs large investment
   C. Has no history
   D. Has no storage
   Answer: B. It integrates all sources for decision making. (Key point: Enterprise warehouse)

## Related in Data Mining

- [Data warehouse, data mart and need](https://www.bctengineer.com/question.md?key=semester_7%2Fdata_mining%3Awarehouse-datamart-need) — Data Mining, chapter 1
- [Define data mart](https://www.bctengineer.com/question.md?key=semester_7%2Fdata_mining%3Adefine-data-mart) — Data Mining, chapter 1
- [Data warehouse architecture and components](https://www.bctengineer.com/question.md?key=semester_7%2Fdata_mining%3Adw-architecture-components) — Data Mining, chapter 1
- [Data warehouse schemas](https://www.bctengineer.com/question.md?key=semester_7%2Fdata_mining%3Adw-schema-types) — Data Mining, chapter 1
- [Short note: Noise in data warehouse](https://www.bctengineer.com/question.md?key=semester_7%2Fdata_mining%3Anoise-in-dw-note) — Data Mining, chapter 2
- [Data warehouse and its characteristics](https://www.bctengineer.com/question.md?key=semester_7%2Fdata_mining%3Adw-define-characteristics) — Data Mining, chapter 1

## Related in other subjects

- [Data warehouse and data mining](https://www.bctengineer.com/question.md?key=semester_8%2Finformation_system%3Adata-warehouse-data-mining) — Information System, chapter 4, asked 2×
- [Hybrid data in big data warehouse](https://www.bctengineer.com/question.md?key=semester_8%2Fbig_data_technologies%3Ahybrid-data-warehouse) — Big Data Technologies, chapter 1