The slowest part of many ASP.NET Core applications is calls to data stores or other remote services. Because of this, it's critical to minimize and optimize such calls.
Several options are available for improving performance in these areas:
- Data that can be slightly stale (a minute or two out-of-date, perhaps) can be cached so that they don't need to be queried for every request.
- When retrieving data, try to condense data access into as few queries as possible. In some cases, it's even worthwhile to preemptively query for some extra rows if you know that the current request is likely to be followed by others that will need that data and it can be cached as part of this data store access.
- Make sure to only query for necessary data. Don't retrieve rows that aren't
used. Similarly, make sure that LINQ filters and aggregators (
Where,Select,Sum, etc.) run before resolving the LINQ query (by iterating over it or usingToList, for example) so that those operations are completed by the database and extra data isn't returned to your service.