## Metadata - Author: [[google-cloud|Google Cloud]] - Full Title:: Understanding Symmetric Aggregates - Category:: #🗞️Articles - Document Tags:: [[looker|Looker]], - URL:: https://cloud.google.com/looker/docs/best-practices/understanding-symmetric-aggregates - Finished date:: [[2023-06-30]] ## Highlights > Symmetric aggregates prevent analysts — and anyone else who uses Looker — from accidentally miscalculating aggregates such as sums, averages, and counts ([View Highlight](https://read.readwise.io/read/01h45bakqh4gqzpbnfkngjrbjp)) > Symmetric aggregates do this by making sure to count each fact in the calculation the correct number of times as well as by keeping track of what you're calculating. ([View Highlight](https://read.readwise.io/read/01h45bb2q8rxkz05yh8amxvjj0)) > the symmetric aggregates function recognizes that `total` is a property of `orders` (not `order_items`), so it needs to count each order's total only once to get the correct answer ([View Highlight](https://read.readwise.io/read/01h45bchhzhk7cvg3rby4cfwbb)) > symmetric aggregates impose some performance costs ([View Highlight](https://read.readwise.io/read/01h45bx3tvdw0sf49yz5kpppyn))