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Databases & SQL vocabulary · Data Modeling and Normalization

Denormalization

Meaning in databases & SQL, with examples

/diːˌnɔːrmələˈzeɪʃən/nounCommon term

In databases & SQL, denormalization means: Deliberately storing some data in more than one place, or combining tables, to make reads faster, while accepting more work to keep the copies correct.

In Turkish: denormalizasyon, normalizasyonu bozma

How it is used

Common in reporting databases, data warehouses and NoSQL designs. Examples include storing an order total instead of calculating it or copying the customer name into the orders table. It should be a conscious decision after normalizing, not an excuse for poor design.

Example sentences

  1. We accepted some denormalization in the reporting tables to avoid eight-table joins.

  2. Denormalization speeds up the product page, but now the price is stored in two places.

Common collocations

  • denormalize a table
  • deliberate denormalization
  • denormalized data
  • read performance
  • normalizationThe process of organizing tables so that each fact is stored in only one place, which reduces repeated data and prevents update mistakes.
  • normal formOne of a series of rules for table design (1NF, 2NF, 3NF and higher); each level removes a particular kind of repeated or badly placed data.
  • data warehouseA central database built for reporting and analysis that collects historical data from many systems and is designed for large read queries rather than small updates.
  • document databaseA NoSQL database that stores each item as a self-contained document, usually in a JSON-like format, so related data can be kept together without fixed tables.

This word in other fields

The same English word can have a different meaning in another field:

More terms: Data Modeling and Normalization

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