Update ef-core-query-cache.md

Author: waqasm78

docs2/pages/ef-core-docs/documentations/query-cache/ef-core-query-cache.md

@@ -30,3 +30,53 @@ var countries2 = ctx.Countries.FromCache().ToList();
 
 ```
 [Try it](https://dotnetfiddle.net/EZZkhP)
+
+## Scenarios
+
+ - [Query Criteria](scenarios/ef-core-query-cache-using-query-criteria.md)
+ - [Query Deferred](scenarios/ef-core-query-cache-query-deferred.md)
+ - [Tag & ExpireTag](scenarios/ef-core-query-cache-tag.md)
+ - [Expiration](scenarios/ef-core-query-cache-expiration.md)
+ - [Query Cache Control](scenarios/ef-core-query-cache-control.md)
+ 
+## Real Life Scenarios
+
+ - Caching read-only data like application configuration.
+ - Caching data that cQuery Cache Controlan only be modified via an importation like states & countries and make all cache entries related expired once the importation is completed (Tag Expiration).
+ - Caching data that are frequently accessed but rarely modified like comments and expire the tag when a new comment is added or after one hour without any access (Tag Expiration & Sliding Expiration).
+ - Caching statistics that don't require to be live like client count and expire them every hour (Absolute Expiration).
+
+## Behind the code
+
+When **FromCache** is invoked, The QueryCacheManager returns the result if a cache entry exists for the cache key. If no cache entry exists, the query is materialized then cached in the memory using the cache key before being returned. If a cache tag is specified, the cache key is also stored in a concurrent dictionary for all tags.
+
+ - **The Cache:** The memory cache is used by default.
+
+ - **The Cache Key:** The cache key is created by combining a cache prefix, all cache tags and the query expression.
+
+ - **The Query Materialized:** The query is materialized by either using "ToList()" method or "Execute()" method for query deferred.
+
+## Limitations
+
+ - Entity Framework Core:
+   - **DO NOT** support Cache Query Deferred (May be available when EF Core will be more stable)
+
+## Requirements
+
+ - **EF+ Query Cache:** Full version or Standalone version
+ - **Database Provider:** All supported
+ - **Entity Framework Version:** EF Core
+ - **Minimum Framework Version:** .NET Framework 4
+
+## Conclusion
+
+As we have seen, EF+ Query Cache follows a good architecture principle:
+
+ - **Flexible:** Tag & Cache Options make it possible to use Query Cache in a various number of scenarios.
+ - **Extensible:** If there is something missing, the library creates your own extension method or your own cache to overcome the problem.
+ - **Maintainable:** The easy to use API, documentation and available source code allows new developers to quickly understand this feature.
+ - **Scalable:** Caching gets only better as the number of user/traffic grows by drastically reducing database round trip.
+
+Need help getting started? [[email protected]](mailto:[email protected])
+
+We welcome all comments, ideas and suggestions to improve our library.