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Documentation for Entity Framework Core and Entity Framework 6
https://docs.microsoft.com/ef/
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Clarify how EF uses indexes (i.e. currently only for update ordering) #1677

Open smcga opened 5 years ago

smcga commented 5 years ago

I understand that when using migrations, indexes defined in OnModelCreating will be created in the database.

I have an existing database, with indexes already set up, and was wondering if there is a benefit to defining these indexes in my DbContext? Does EFCore use these index definitions to influence how it builds queries, or does defining an existing index have no effect?

Thanks

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smcga commented 5 years ago

I found an answer for this on SO - https://stackoverflow.com/questions/54299018/what-is-the-benefit-of-adding-hasindex-in-your-mappings-on-a-dbfirst-scenari

tl;dr - If you are not updating the DB with migrations, this does nothing.

offirpeer commented 4 years ago

If I created an index in my DB, how can I tell EF to use it when fetching the data? https://stackoverflow.com/questions/62881671/ef-core-not-fetching-data-from-table-based-on-its-clustered-index