How the cache is stored

Hi, what kind of cache library do you use?
How to solve the problem of multiple keys?
Here is a similar problem:
https://stackoverflow.com/questions/59103206/how-to-cache-an-object-with-multiple-keys-in-c-sharp
The solution is interesting, but it makes the cache constant and can overflow (no expiry date of the item)

Which is better, storage in ram or e.g. redis? The app isn't big, just one server.

https://github.com/dotnetcore/EasyCaching
Anyone using this? Is it better than Microsoft's default?

most of the time we just use MemoryCache

right?

Yeah, just services.AddMemoryCache(); then you can inject IMemoryCache

Is it possible to clear the cache?
I used to test it but without a key I had a problem with it. I had to restart the application to clear the cache.

Unsure, never had to clear the whole cache. I guess you could wrap the cache and add a set of keys and clear if needed but feels hacky

You can remove stuff but you need a key as you stated.

Anyone know how to make multiple keys? Apparently it's called a tag

Not sure what you mean

I found a similar problem here.

The point is for one value to have many keys.

in other programming languages this is called tags

Unfortunately, I have searched the documentation and I do not see such an option.

Can you point to this tag concept in other programming languages?

Just looking, can't find it right now.
I saw in node and PHP that there are "tags"
Thanks to this, you can have many keys, for example:
There is a user, has an ID, Name, E-mail, telephone number and full name
You can search for it by ID, Name, E-mail and Phone
e.g.
1 | User | user@example.com | +11 111 111 111 | John | Smith
search by id 1= John Smith
serch by name User = John Smith
search by mail user@example.com = John Smith

Well if you are willing to do a linear search you can obviously search for objects by any property. If you want an efficient search there are a variety of options (for instance, keep the data sorted and do a binary search, or build some kind of index) but for something like a dictionary (which is based on hash tables) there is no magic way to do a fast lookup on multiple different properties - that's not how hash tables work.

And MemoryCache uses a dictionary internally