---
title: "Uses of OLAP; OLAP vs OLTP"
subject: "Data Mining"
chapter: 2
key: "semester_7/data_mining:olap-uses-compare-oltp"
source: https://www.bctengineer.com/q/semester_7/data_mining/olap-uses-compare-oltp
site: BCT Engineering
---

# Uses of OLAP; OLAP vs OLTP

Data Mining · Chapter 2: Data Pre-processing

- Asked in: year not given, 4+6 marks
- Video: [Lec -8 : OLAP vs OLTP | Difference between OLAP vs OLTP with Real Life Examples](https://www.youtube.com/watch?v=DeL3dgiy6vk) — 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/olap-uses-compare-oltp
- Whole chapter: https://www.bctengineer.com/md/semester_7/data_mining/chapter-2

## Question

What are the uses of OLAP? Compare OLAP with OLTP.

## Short answer

OLAP is used for multidimensional business analysis, reporting, budgeting, forecasting, what-if analysis, exception finding, and supporting data mining. OLTP handles daily short transactions with current detailed normalised data, while OLAP handles complex queries over historical summarised multidimensional data.

## Answer

#### Uses of OLAP
- Multidimensional analysis of business data (sales by product, region and time).
- Reports, dashboards and executive information.
- Budgeting, planning and forecasting.
- Trend and what-if analysis, comparing actual and target.
- Finding exceptions and areas needing attention using drill-down.
- Supports data mining by providing summarised, clean multidimensional data.
- Applications: sales and marketing analysis, financial reporting, customer profitability, inventory and supply chain analysis.

#### OLAP vs OLTP
| Point | OLTP | OLAP |
|---|---|---|
| Purpose | Day-to-day transactions | Analysis, decision support |
| Users | Clerks, clients, DBAs | Managers, analysts, executives |
| Data | Current, detailed, flat relational | Historical, summarised, multidimensional |
| Database design | ER model, normalised, application-oriented | Star/snowflake, subject-oriented |
| Access | Read/write, short transactions | Mostly read, complex queries |
| Unit of work | Short, simple transaction | Complex query with aggregates |
| Records per access | Tens | Millions |
| Number of users | Thousands | Hundreds |
| DB size | MB to GB | GB to TB |
| Metric | Transaction throughput | Query response time |

## Check yourself

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

1. Which is a typical use of OLAP?
   A. Multidimensional analysis, forecasting and what-if analysis of business data
   B. Recording each ATM withdrawal as it happens
   C. Enforcing concurrency control on short updates
   D. Storing current operational records for clerks
   Answer: A. OLAP supports analysis, planning and forecasting; recording transactions is OLTP. (Key point: Uses of OLAP)

2. Why is drill-down useful in OLAP applications?
   A. It deletes outliers from the warehouse
   B. It helps find exceptions and areas needing attention by moving to detail
   C. It increases transaction throughput
   D. It normalises the schema
   Answer: B. Drill-down lets analysts investigate unusual summary figures in more detail. (Key point: Drill-down use)

3. Which performance metric matches each system?
   A. OLTP: query response time; OLAP: transaction throughput
   B. Both use transaction throughput
   C. OLTP: transaction throughput; OLAP: query response time
   D. Both use DB size
   Answer: C. OLTP is judged by transactions per unit time, OLAP by how fast complex queries return. (Key point: OLTP vs OLAP metric)

## Related in Data Mining

- [OLAP vs OLTP; OLAP operations, fact, dimension](https://www.bctengineer.com/question.md?key=semester_7%2Fdata_mining%3Aolap-oltp-operations-fact-dimension) — Data Mining, chapter 2
- [OLAP vs OLTP; data cube, operations](https://www.bctengineer.com/question.md?key=semester_7%2Fdata_mining%3Aolap-oltp-data-cube-fact-dimension) — Data Mining, chapter 2
- [OLAP vs OLTP; schema, fact, dimension](https://www.bctengineer.com/question.md?key=semester_7%2Fdata_mining%3Aolap-oltp-schema-fact-dimension) — Data Mining, chapter 2
- [OLAP vs OLTP; schema modeling; star DMQL](https://www.bctengineer.com/question.md?key=semester_7%2Fdata_mining%3Aolap-oltp-schema-star-dmql) — Data Mining, chapter 2
- [Short note: OLAP and OLTP](https://www.bctengineer.com/question.md?key=semester_7%2Fdata_mining%3Aolap-oltp-note) — Data Mining, chapter 2

## Related in other subjects

- [Differentiate OLTP and OLAP](https://www.bctengineer.com/question.md?key=semester_8%2Finformation_system%3Aoltp-vs-olap) — Information System, chapter 4, asked 5×
- [Lumped vs distributed analysis and microwave uses](https://www.bctengineer.com/question.md?key=semester_7%2Frf_and_microwave_engineering%3Alumped-distributed-microwave-uses) — RF and Microwave Engineering, chapter 1