What is a factless fact table example?
For example, a store that did not sell a product for a given period. To produce such a report, you need to have a factless fact table to capture all the possible combinations of products that were on sale. You can then figure out what is missing by comparing the factless table with the sales table for the list of products that did sell.
What is a fact less fact table in ATS?
A tracking process or collecting status can be performed by using fact less fact tables. The fact table does not have numeric values that are aggregate, hence the name. Mere key values that are referenced by the dimensions, from which the status is collected, are available in fact less fact tables.
What is a “fact table”?
In Data Warehouse parlance a “Fact Table” is the central data repository for all transactions related to a subject area.
What is fact less table in event management?
Fact less tables are so called because they simply contain keys which refer to the dimension tables. Hence, they don’t really have facts or any information but are more commonly used for tracking some information of an event.
What is factless fact?
A factless fact table is a fact table that does not have any measures, i.e. any numeric fields that can be aggregated. For example, if you are modelling product sales, you can have a Sales fact table that will contain the dimension keys and, for example, the "amount" value/measure, to record the amount sold.
Why do we need junk dimension?
A junk dimension is a convenient grouping of typically low-cardinality flags and indicators. By creating an abstract dimension, these flags and indicators are removed from the fact table while placing them into a useful dimensional framework.
Why do we need aggregate fact tables?
So the reason why aggregates can make such a dramatic increase in the performance of the data warehouse is the reduction of the number of rows to be accessed when responding to a query. A fact table consists of the measurements, metrics or facts of a business process.
What is true about factless fact table?
A factless fact table is a fact table that does not have any measures. It is essentially an intersection of dimensions (it contains nothing but dimensional keys). There are two types of factless tables: One is for capturing an event, and one is for describing conditions.
What is the use of junk dimension in data warehouse?
The junk dimension is a structure that provides a convenient place to store the junk attributes. It is a collection of random transnational codes, flags and/or text attributes that are unrelated to any particular dimension.
Why do we need dimension tables?
Dimension tables describe the different aspects of a business process. For example, if you are looking to determine the sales targets, you can store the attributes of the sales targets in a dimension table. Dimension tables group the data in the database when the business creates reports.
Can we have two fact tables in a snowflake schema?
A schema can have one or more facts, but these facts are not linked by any key relationship. It is best practice not to join fact tables in a single query as you would whey querying a normalized/transactional database.
What is an aggregation table?
Aggregate tables are tables that aggregate or "roll up" the data to one level higher than a base or derived table (and other functions can also be in the aggregate tables such as average, count, min, max, and others).
What are the different types of fact tables?
The Three Types of Fact TablesTransaction Fact Tables.Periodic Snapshot Tables.Accumulating Snapshot Tables.Why Have They Not Changed?
How many attributes does factless fact table have?
There are two kinds of factless fact tables: Factless fact table describes events or activities. Factless fact table describes a condition, eligibility, or coverage.
What is the main reason of having multi fact?
The reason is simple, it's easy to organize and it's easy to read. If you know your dimension tables and your fact table, you can already answer the question of whether you can aggregate by dimensions or “slice and dice” by categories. The problem occurs when you need to add another fact table to a model.
What is factless fact in Microstrategy?
A factless fact table is table that doesn't have fact at all. They may consist of nothing but keys. There are tow types of factless fact table. 1-> event 2-> coverage.
Factless fact table for event or activity
When designing a dimensional model, you often find that you want to track events or activities that occur in your business process but you can’t find measures to track. In these situations, you can create a transaction-grained fact table that has no facts to describe that events or activities.
Factless fact table for event or activity example
For example, you may want to track employee leaves. How often and why your employee leaves are very important for you to plan your daily activities and resources.
What is a factless table?
Factless Fact Table. A factless fact table is a fact table that does not have any measures. It is essentially an intersection of dimensions. On the surface, a factless fact table does not make sense, since a fact table is, after all, about facts.
Why is adding a fact that always shows 1 redundant?
However, adding a fact that always shows 1 is redundant because we can simply use the COUNT function in SQL to answer the same questions.
What is a fact table?
Fact table - A table having facts, which are used to measure the performance of the business using the primary key of the dimension table. So, there could be one fact table to capture number of one particular product sold from a Store one a given period.
How many child tables are there in an application?
A application may have one child table or 40 child tables or any number between 1-40 and unknown number of child row in each child table.
Can there be one fact table?
So, there could be one fact table to capture number of one particular product sold from a Store one a given period . If that particular product is not sold from that store in that given period, then in that table there will be no fact only primary keys of each dimension table will available.
What is a factless table?
Factless fact table. A factless fact table is a fact table that does not have any measures. It is essentially an intersection of dimensions (it contains nothing but dimensional keys). There are two types of factless tables: One is for capturing an event, and one is for describing conditions.
What are the two types of factless tables?
There are two types of factless tables: One is for capturing an event, and one is for describing conditions. An event establishes the relationship among the dimension members from various dimensions, but there is no measured value. The existence of the relationship itself is the fact.
What is the purpose of Factless Fact Table?
Fact less tables are so called because they simply contain keys which refer to the dimension tables. Hence, they don’t really have facts or any information but are more commonly used for tracking some information of an event.
What is the purpose of Factless Fact Table?
A tracking process or collecting status can be performed by using fact less fact tables. The fact table does not have numeric values that are aggregate, hence the name. Mere key values that are referenced by the dimensions, from which the status is collected, are available in fact less fact tables.
About Factless Fact Table
This tutorial assumes that the reader is familiar with SQL Server database and data warehouse business intelligence concepts. As well as is comfortable with the common terms used and applied in this field (of business intelligence).
When to use Factless FACT Tables
In order to understand the use of Factless FACT table we have to refer to, Kimball Group, one of the earliest pioneers in the field of Data Warehouse. According to Kimball Group, "It is possible that the event merely records a set of dimensional entities coming together at a moment in time.
How to use FactLess FACT Table
Let us now look at a common example of how to use a Factless Fact table.