What indices did you use at work? What did you apply in practice? In Wildberries?

In working with databases, I often used B-tree indexes to speed up searches by keys and ranges, as well as hash indexes for quick point lookups where supported. At Wildberries, a wide range of indexes was used, including composite indexes to optimize complex queries, as well as full-text indexes for searching product descriptions. Additionally, partial indexes were actively used to optimize queries with filters, and expression indexes for specific conditions. It was important to balance the number of indexes with the speed of data insertion/update to avoid degrading write performance.