In dimensional modelling the first phase is toa.Identify grainb.Identify business processc.Identify tablesd.identify facts

In dimensional modelling, the first phase is to identify the business process. This involves understanding the business requirements, the data sources available, and the key performance indicators (KPIs) that the business wants to track.

Here are the steps in order:

1. Identify Business Process: The first step in dimensional modeling is to identify the business process. This is the real-world subject matter that you are trying to model, such as sales, inventory, or customer management.

2. Identify Grain: The next step is to identify the grain, which is the level of detail that the model will represent. For example, in a sales model, the grain might be individual transactions.

3. Identify Facts: After identifying the grain, the next step is to identify the facts, or the numerical or quantitative information that the business wants to track. In a sales model, this might include the number of units sold, total sales, and total profit.

4. Identify Tables: The final step is to identify the tables, or the structure in which the data will be stored. This includes fact tables, which store the facts, and dimension tables, which store the descriptive information about the facts.