---
title: "Define apex cuboid"
subject: "Data Mining"
chapter: 2
key: "semester_7/data_mining:define-apex-cuboid"
source: https://www.bctengineer.com/q/semester_7/data_mining/define-apex-cuboid
site: BCT Engineering
---

# Define apex cuboid

Data Mining · Chapter 2: Data Pre-processing

- Asked in: year not given
- Video: [Data Cube in Data Warehousing | Learn in 6-Mins](https://www.youtube.com/watch?v=tRfYT1wDx3g) — Kognito Key
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_7/data_mining/define-apex-cuboid
- Whole chapter: https://www.bctengineer.com/md/semester_7/data_mining/chapter-2

## Question

Define apex cuboid.

## Short answer

The apex cuboid is the highest-level 0-dimensional cuboid that aggregates over all dimensions, storing a single grand total value (usually "all"). Example: in a sales cube with time, item, location, the apex cuboid holds total sales across all time, all items, and all locations.

## Answer

The **apex cuboid** is the highest-level, 0-dimensional cuboid of a data cube lattice. It aggregates over all dimensions and holds a single value: the grand total of the measure, usually written "all".

**Example**: in the sales cube (time, item, location), the apex cuboid stores one cell, the total sales over all time, all items and all locations. It is the top of the lattice, while the 3-D cuboid is the base cuboid.

## Check yourself

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

1. What is the apex cuboid?
   A. The 0-dimensional cuboid holding the grand total over all dimensions
   B. The most detailed n-D cuboid
   C. A cuboid with only one dimension
   D. A cuboid with no measures
   Answer: A. The apex aggregates everything into a single value, written 'all'. (Key point: Apex cuboid)

2. How many cells does the apex cuboid store?
   A. One per dimension
   B. One
   C. 2^n
   D. As many as the base cuboid
   Answer: B. It holds a single grand-total value. (Key point: Cells in apex)

3. Where do the apex and base cuboids sit in the lattice?
   A. Both at the top
   B. Apex at the bottom, base at the top
   C. Apex at the top (most summarised), base at the bottom (most detailed)
   D. Both are in the middle
   Answer: C. Apex is the top of the lattice, base the lowest level. (Key point: Apex vs base)