Relational Database Terminology: Record, Relation, Tuple, and Attribute

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Sep 12, 2026

In the relational model, a record is best understood as a tuple—i.e., one row instance within a relation (often called a table in practice). The attribute corresponds to a column (a component of tuples), not to the whole record. The option (i) criterion is not part of the standard relational-model vocabulary for “record” as used in database theory questions.

To ground the intuition: a schema defines the attributes (columns), the relation is the set of tuples (rows), and each tuple is a record-like unit containing one value for every attribute.

Memory Hook

If it answers “What row is this?” → tuple/record. If it answers “What column is this?” → attribute. If it answers “What set of rows?” → relation.

Why (i) is usually wrong

“Criterion” usually refers to a predicate used for filtering (e.g., WHERE conditions), not the relational-model entity corresponding to a record.

Choose the Correct Term for “a record”

1
Step 1
“A record” refers to a single observed item within a table—one row instance.
2
Step 2
Relational model separates: schema (columns) vs relation (collection of rows) vs tuple (one row).
3
Step 3
A single row = a tuple → option (iii).
4
Step 4
Option (ii) is a whole set (relation), option (iv) is a column descriptor (attribute), option (i) is not standard for “record.”

Concept Check (Record vs Relation vs Attribute vs Criterion)

How Relational Terms Fit Together

Define attributes

Schema

Specify attribute names and domains (e.g., StudentID, Name, Major)."

Collect tuples

Relation

A relation is the set of all tuples that match the schema."

One record = one tuple

Tuple

Each tuple is one “record” (one row’s worth of attribute values)."

Mapping of Relational Entities to Table Intuition

Which option best matches “a record”? (Higher score = better match).

Final Answer

A relational database developer refers to a record as (iii) a tuple.

Key term relationships:

Tuple ↔ record (one row instance)
Relation ↔ the whole table’s contents (set of rows)
Attribute ↔ a column/field name (schema component)
Criterion ↔ typically a query condition, not a record entity

Knowledge Check

Question 1 of 4

Q1Single choice

In the relational model, what does a record correspond to?

A relation

A criterion

A tuple

An attribute

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