As discussed in #5703:

I initially started building adapters like kv and typed_kv just for fun, exploring the potential of OpenDAL. These adapters were designed to be simple and primarily optimized for implementing services in an easy way.

However, over time, some users have begun using services built on kv and typed_kv more seriously, resulting in additional feature requests. For example, see #5701 and #5623.

Those factors combined made me wonder whether it's a good idea for us to keep both of those adapters. It seems we can simply retain KvReader and KvWriter, allowing services to use them directly instead of having to implement them each time. This also unlocks the potential for services to introduce more features without adding another layer of unnecessary abstraction.

Maybe we could migrate services to implement Access directly and reuse the components we already have. This would allow the community to implement great features, such as reading ranges from SQLite, more easily.

Let's start migrating adapter based services. This migration should not break any existsing services.

Tasks

• cacache: refactor: Migrate services cacache to implement Access #6303
• cloudflare_kv: refactor: Migrate cloudflare_kv from adapter::kv to Access instead #6340
• d1: refactor: migrate d1 service from adapter::kv to impl Access directly #6725
• dashmap: refactor: Migrate dashmap service to implement Access directly #6344
• etcd: refactor: Migrate etcd service to implement Access directly #6420
• foundationdb: refactor: migrate foundationdb service from adapter::kv to impl Access directly #6722
• gridfs: refactor: migrate gridfs service from adapter::kv to impl Access directly #6726
• memcached: refactor: migrate memcached service from adapter::kv to impl Access directly #6714
• memory: refactor: Migrate memory service to implment Access directly #6301
• mini_moka: refactor: Migrate mini_moka service to implement Access directly #6316
• moka: refactor: Migrate moka from adapter::typed_kv to Access instead #6300
• mongodb: refactor: migrate mongodb service from adapter::kv to impl Access directly #6724
• mysql: refactor: migrate mysql service from adapter::kv to impl Access directly #6716
• persy: refactor: migrate persy service from adapter::kv to impl Access directly #6721
• postgresql: refactor: migrate postgresql service from adapter::kv to impl Access directly #6718
• redb: refactor: migrate redb service from adapter::kv to impl Access directly #6733
• redis: refactor: Migrate redis from adapter::kv to Access instead #6291
• rocksdb: refactor: migrate rocksdb service from adapter::kv to impl Access directly #6732
• sled: refactor: migrate sled service from adapter::kv to impl Access directly #6731
• sqlite: refactor: Migrate sqlite from adapter::kv to Access instead #6328
• surrealdb: refactor: migrate surrealdb service from adapter::kv to impl Access directly #6723
• tikv: refactor: migrate tikv service from adapter::kv to impl Access directly #6713