The ESR rule: how compound indexes really get used
Equality, Sort, Range — the three letters that decide whether your compound index is a thoroughbred or a paperweight. We dissect the planner's prefix-matching logic on a 40M doc collection.
Equality, Sort, Range — the three letters that decide whether your compound index is a thoroughbred or a paperweight. We dissect the planner's prefix-matching logic on a 40M doc collection.
If your index has every column the query needs, the database never has to fetch the row. Here's how to recognise the opportunity — and the storage trade.