# Symmetric Aggregates Symmetric aggregates allow Zenlytic to calculate your metrics accurately even when there's a situation where the joins make that very difficult by duplicating the values to aggregate. We could go in-depth into how we do this, but we're obviously not the first to do this, and Looker has already written the best piece of content about this [here](https://cloud.google.com/looker/docs/best-practices/understanding-symmetric-aggregates), which we strongly recommend checking out. ## Examples You can use `distinct` aggregates to tell Zenlytic how to distinctly calculate your metric. For example, this measure is a sum, but uniquely for each `order_id`. ```yaml - name: total_price_order_level field_type: measure type: sum_distinct sql_distinct_key: ${order_id} sql: ${price} ``` --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.zenlytic.com/data-modeling/symmetric_aggregates.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.