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DP-900 · Question #223

In a fully normalized database, how is data read and written for a single entity?

The correct answer is D. Data is read from multiple tables and written to a single table. In a fully normalized database, data for a single entity is distributed across multiple tables (eliminating redundancy), so reads require JOINs across tables, but because each fact exists in exactly one place, a single entity update writes to only one table.

Submitted by renata2k· Mar 30, 2026Identify considerations for relational data on Azure

Question

In a fully normalized database, how is data read and written for a single entity?

Options

  • AData is read from multiple tables and written to multiple tables.
  • BData is read from a single table and written to a single table.
  • CData is read from a single table and written to multiple tables.
  • DData is read from multiple tables and written to a single table.

How the community answered

(52 responses)
  • A
    10% (5)
  • B
    2% (1)
  • C
    6% (3)
  • D
    83% (43)

Why each option

In a fully normalized database, data for a single entity is distributed across multiple tables (eliminating redundancy), so reads require JOINs across tables, but because each fact exists in exactly one place, a single entity update writes to only one table.

AData is read from multiple tables and written to multiple tables.

Writing to multiple tables would indicate either a denormalized schema or a multi-entity transaction, not the standard behavior of updating a single, fully normalized entity.

BData is read from a single table and written to a single table.

Reading from a single table and writing to a single table describes a flat, denormalized structure, not a fully normalized relational schema where data is split across related tables.

CData is read from a single table and written to multiple tables.

Reading from a single table but writing to multiple tables is not consistent with how normalization works; normalization reduces write targets by storing each fact in one place.

DData is read from multiple tables and written to a single table.Correct

Normalization eliminates data redundancy by decomposing data into related tables linked by foreign keys. Reading a complete entity requires joining multiple tables to reassemble the data. However, because each attribute is stored in exactly one canonical table, updating a discrete entity attribute requires writing to only that one table, avoiding the anomalies that come with duplicated data.

Concept tested: Database normalization read and write behavior

Source: https://learn.microsoft.com/en-us/office/troubleshoot/access/database-normalization-description

Topics

#normalization#relational database#data modeling#table joins

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