Talk:Fact table

Article begins with circular definitions
The first two paragraphs introducing a fact table essentially define it as a table that contains facts (or synonyms for facts)

Examples:

1. a fact table consists of the measurements, metrics or facts

To lay readers this statements is: "a fact table consists of the facts"

2. A fact table typically has two types of columns: those that contain facts and those that are a foreign key to dimension tables.

Again, the definition is a fact table contains facts

3. Fact tables are often defined by their grain. The grain of a fact table represents the most atomic level by which the facts may be defined.

Here a fact table is define by a grain is in turn defined as the smallest fact.

The link to the definition of fact does not help, as the linked definition is also circular. A fact is a value, or measurement, which represents a fact about the managed entity or system

Can someone please help out by adding a clear definition that does not use circular logic as the lead in to the wiki article. Please do so without just defining it as a synonym for facts. — Preceding unsigned comment added by 206.218.52.35 (talk) 17:28, 10 April 2019 (UTC)


 * It's not circular, it's a wikilink to Fact (data warehouse). It does assume that you're going to navigate that link to make it comprehensible, so expanding the definition here might be useful. Andy Dingley (talk) 17:36, 10 April 2019 (UTC)

summary records in fact table
Several sources suggest that you should NOT add summary information to a fact table. For example here: "Do not mix granularities in the fact table. Do not add summary records to the fact table that include detail facts already in the fact table. Aggregation summary records, if used, must be stored in separate tables, one table for each level of granularity." Yet the example on this page does so. dfrankow (talk) 23:27, 23 January 2012 (UTC)

"Junction" table
The "fact-less fact" table is most analogous to a "junction" table, and I find authors commonly writing "(junction table)" in quotes after the term "fact-less fact table". Jtankers (talk) 22:17, 21 January 2010 (UTC)

Are accumulating snapshots poor form?
According to the star schema article, fact tables are usually in 3NF. However, by the description of an accumulating snapshot, it may contain null fields, and thus is not even in 1NF. It should either be noted here that they are in poor form, or are an exception to the "usual" rule for star schemas. — Preceding unsigned comment added by Qseep (talk • contribs) 00:02, 10 February 2011 (UTC)

Steps in designing a fact table
If the Kimball approach in the citation is the alternative - what is the source for the method actually given in the article? — Preceding unsigned comment added by Infojunkie23 (talk • contribs) 14:04, 7 March 2014 (UTC)

Main Image Contains Non-English Text
The main image ( https://commons.wikimedia.org/wiki/File:Esquema_en_estrella.png ) contains important information that is written in Spanish. We should find an English version of this image.