What is a write thru cache? What are the other types of caches?
Write-through cache: Under this scheme, data is written into the cache and the corresponding database simultaneously. The cached data allows for fast retrieval and, since the same data gets written in the permanent storage, we will have complete data consistency between the cache and the storage.
Take a look at the following lesson for other cache invalidation schemes - https://www.educative.io/courses/grokking-the-system-design-interview/3j6NnJrpp5p#div-stylecolorblack-background-colore2f4c7-border-radius5px-padding5px-cache-invalidationdiv