What is factless fact in data warehouse?
Factless fact tables are only used to establish relationships between elements of different dimensions. And are also useful for describing events and coverage, meaning tables contain information that nothing has happened. It often represents many-to-many relationships. The only thing they have is an abbreviated key.
What fact table contains?
A fact table stores quantitative information for analysis and is often denormalized. A fact table works with dimension tables. A fact table holds the data to be analyzed, and a dimension table stores data about the ways in which the data in the fact table can be analyzed.
What is fact table and Factless table?
Factless facts are those fact tables that have no measures associated with the transaction. Factless facts are a simple collection of dimensional keys which define the transactions or describing condition for the time period of the fact.
How many attributes does factless fact table have?
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 meaning of Factless?
Lacking facts; inaccurate or fictional
factless (comparative more factless, superlative most factless) Lacking facts; inaccurate or fictional.
What are the 3 types of SCD?
Introduction to Slowly Changing Dimensions (SCD)
- Type 1 – This model involves overwriting the old current value with the new current value.
- Type 2 – The current and the historical records are kept and maintained in the same file or table.
- Type 3 – The current data and historical data are kept in the same record.
What are the 3 types of fact tables?
There are three types of fact tables and entities: Transaction. A transaction fact table or transaction fact entity records one row per transaction. Periodic.
What are the three types of facts?
We can divide the Facts in to these three types.
- Non-Additive.
- Semi-Additive.
- Additive.
What is factless fact example?
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.
What are the types of fact tables?
What is SCD Type 1 and SCD Type 2?
Type 1 dimension mapping (SCD1): This keeps only current data and does not maintain historical data. Note : Use SCD1 mapping when you do not want history of previous data. Type 2 dimension/version number mapping (SCD2): This keeps current as well as historical data in the table.
What is SCD Type 2 in data warehouse?
SCD2 is a dimension that stores and manages current and historical data over time in a data warehouse. The purpose of an SCD2 is to preserve the history of changes.
Which one is correct Molap Mcq?
Which one is correct regarding MOLAP? Data is stored and fetched from the main data warehouse. Large volume of data is used. A and B is correct.
What is true about data warehouse Mcq?
A system that is used to run the business in real time and is based on historical data.
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Exercise :: Data Warehousing – General Questions.
| A. | A process to reject data from the data warehouse and to create the necessary indexes |
|---|---|
| D. | A process to upgrade the quality of data before it is moved into a data warehouse |
What is fact table and its types?
A fact table stores quantitative information for analysis and is often denormalized. A fact table works with dimension tables and it holds the data to be analyzed and a dimension table stores data about the ways in which the data can be analyzed. Thus, a fact table consists of two types of columns.
What are the types of facts?
There are three types of facts: Summative facts: Summative facts are used with aggregation functions such as sum (), average (), etc. Semi summative facts: There are small numbers of quasi-summative fact aggregation functions that will apply. For example, consider bank account details.
What are three types of facts?
How many types of SCDs are there?
There are three types of SCDs and you can use Warehouse Builder to define, deploy, and load all three types of SCDs. What are the three types of SCDs?
What is MOLAP ROLAP and Holap?
MOLAP. HOLAP. ROLAP stands for Relational Online Analytical Processing. MOLAP stands for Multidimensional Online Analytical Processing. HOLAP stands for Hybrid Online Analytical Processing.
Which of the following is not a kind of data warehouse application Mcq?
| Q. | Which of the following is not a kind of data warehouse application? |
|---|---|
| B. | analytical processing |
| C. | data mining |
| D. | transaction processing |
| Answer» d. transaction processing |
Which of the following statement is applicable to the data warehouse Mcq?
| Q. | Which of the following statement is true? |
|---|---|
| B. | The data warehouse is used as a source for the operational data |
| C. | The operational data are used as a source for the data warehouse |
| D. | All of the above |
| Answer» c. The operational data are used as a source for the data warehouse |
What are the 4 types of slowly changing dimensions?
What are Slowly Changing Dimensions
| SCD Type | Summary |
|---|---|
| Type 1 | Overwrite the changes |
| Type 2 | History will be added as a new row. |
| Type 3 | History will be added as a new column. |
| Type 4 | A new dimension will be added |
Which of the following is an advantage of MOLAP Mcq?
What is the advantage of Molap? Molap lets you store, analyze, and manage the multidimensional data. Its cache, storage, and indexing features allow you to perform fast query operations. It provides small sizes of data as compared to relational databases.
Which is faster MOLAP or HOLAP?
Processing time of MOLAP is fast. Processing time of HOLAP is fast.