- ndexes significantly reduce the amount of work required to fetch documents. Without the proper indexes, the only way to satisfy a query is to scan all documents linearly until the query conditions are met. This frequently means scanning entire collections.
- Only one single-key index will be used to resolve a query. For queries containing multiple keys (say, ingredient and recipe name), a compound index containing those keys will best
resolve the query.
Index, Single vs compound, compound redundancy, compound order
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