The main idea behind one big table (OBT) is to join all of the data necessary for analytics into wide denormalized tables. One big table is a popular approach to serving analytics at larger scales and takes advantage of the benefits of columnar databases. It’s usually combined with/built on top of other techniques such as a Dimensional Model or Data Vault.
Tip
You can use OBT when starting new data warehouse to provide value immediately while another longer-term approach is worked on like a Dimensional Model or a Data Vault.
One Big Table Advantages
- Increases query performance by removing the need for joins.
- Simple to query.
One Big Table Disadvantages
- Very wide tables can get messy to read and maintain.
- Does not adapt to changes well. Adding new data sources will require rebuilding the table.