Hi Partner,
Here's a brief description about rollup query
Rollup query
Rollup queries help you gather data about a goal and all child goals. Thinking back to the business scenario about goals, XYZ’s sales managers wanted sales people on their team to track individual goals. A rollup query can be used to gather the data to measure the goals against.
Here is an example of a Rollup Query to measure a sales rep’s actual revenue. We want to measure “Won” Opportunities where the Actual Revenue is greater than $100 and the Account related to the Opportunity has an Account Type of “Customer”.

Creating rollup queries
To create a rollup query, follow these steps:
1. Start CRM, go to the Sales module, and then click on Rollup Queries.
2. On the Rollup Queries ribbon bar, in the Records group, click on New.

3. Enter the following required fields:
i. Name: Enter a clear, concise name for the rollup query
ii. Owner: Defaults to the currently logged in user
iii. Entity Type: Define the entity for which this query will be run
4. Under Query, use the controls to add the criteria for your query. The criteria that you can add depends on the entity type you have chosen.
5. To test the query, click on View Records.
6. Click on Save and Close.