---
title: "Short note: OLAP and OLTP"
subject: "Data Mining"
chapter: 2
key: "semester_7/data_mining:olap-oltp-note"
source: https://www.bctengineer.com/q/semester_7/data_mining/olap-oltp-note
site: BCT Engineering
---

# Short note: OLAP and OLTP

Data Mining · Chapter 2: Data Pre-processing

- Asked in: year not given, 3 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-oltp-note
- Whole chapter: https://www.bctengineer.com/md/semester_7/data_mining/chapter-2

## Question

Write a short note on OLAP and OLTP.

## Short answer

OLTP processes many short daily transactions such as inserts, updates, deletes on current detailed normalised data. OLAP supports analysis and decision making with complex queries over historical summarised multidimensional data, using roll-up, drill-down, slice, dice and pivot operations.

## Answer

**OLTP (Online Transaction Processing)** handles the day-to-day operations of an organisation: many short transactions such as insert, update, delete (bank deposit, ticket booking). Data is current, detailed and normalised, and the main concerns are speed of transactions, consistency and concurrency.

**OLAP (Online Analytical Processing)** supports analysis and decision making: complex queries over large historical, summarised, multidimensional data. It offers operations such as roll-up, drill-down, slice, dice and pivot.

| 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 an OLTP workload?
   A. Many short insert/update transactions such as bank deposits or ticket booking
   B. Complex aggregate queries over years of history
   C. Roll-up and pivot over a cube
   D. Decision support for executives
   Answer: A. OLTP handles day-to-day short transactions. (Key point: OLTP definition)

2. Which set lists operations offered by OLAP?
   A. Insert, update, delete, commit
   B. Roll-up, drill-down, slice, dice, pivot
   C. Normalise, denormalise, index, hash
   D. Sort, bin, smooth, clean
   Answer: B. OLAP offers roll-up, drill-down, slice, dice and pivot on multidimensional data. (Key point: OLAP operations)

3. Roughly how many records does a typical access touch?
   A. OLTP: millions; OLAP: tens
   B. Both: millions
   C. OLTP: tens; OLAP: millions
   D. OLTP: thousands; OLAP: hundreds
   Answer: C. OLTP touches few records per transaction while OLAP queries scan millions. (Key point: OLTP vs OLAP records per access)

## 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
- [Uses of OLAP; OLAP vs OLTP](https://www.bctengineer.com/question.md?key=semester_7%2Fdata_mining%3Aolap-uses-compare-oltp) — 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×