The maximum number of superkeys for the relation schema R (E, F, G, H) with E as the key is …

Integrity Constraints and Normal Forms

GATE CSE 2014 Set 2 · Q21

NAT1 markEasy

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The maximum number of superkeys for the relation schema $\text{R} (\text{E}, \text{F}, \text{G}, \text{H})$ with $\text{E}$ as the key is _______.

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Official answer: 8

Integrity Constraints and Normal Forms

A relation schema $R(E, F, G, H)$ has 4 attributes.

A superkey is any superset of a candidate key. Given that $E$ is the key, any subset of attributes of $R$ containing $E$ is a superkey.

The remaining attributes are $\{F, G, H\}$ , which consists of $3$ attributes.

Each of the other 3 attributes can either be included or excluded from the superkey:

\text{Number of superkeys} = 2^3 = 8

The 8 superkeys are:

$\{E\}$
$\{E, F\}$
$\{E, G\}$
$\{E, H\}$
$\{E, F, G\}$
$\{E, F, H\}$
$\{E, G, H\}$
$\{E, F, G, H\}$

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This Integrity Constraints and Normal Forms previous year question is Q21 of the GATE CSE 2014 Set 2 paper. Find more GATE CSE PYQs on Integrity Constraints and Normal Forms in Databases, or browse all GATE CSE PYQs.

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Integrity Constraints and Normal Forms in GATE CSE

Integrity Constraints and Normal Forms has 30 GATE CSE PYQs across 20 papers from 2011 to 2026. 4 of them are 1-mark NAT questions like this one, and GATE CSE 2014 Set 2 has 2.

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Independent practice explanation verified by the GateAI team. GATE is conducted by the IITs; question text follows the official paper.