使用键值存储构建应用程序的设计策略

Question

Key-value store, a type of NoSQL, how can it be used to build common application functions?

• Storing user information (login information)
• Storing documents and/or "entities" with relation to a user or other entities

What is the general strategy in modeling application that uses Key-Value store instead of a typical document NoSQL?

For example if you only have this API to interface to the datastore:

put(String bucketName, String, byte[] value);
byte[] get(String bucketName, String key);
List<String> getKeys(String bucketName, String prefix, int maxKeys);
delete(String bucketName, String key); 

Answer 1

One answer to this question as described here .

Is to model information like this:

[key]           [value]
artist:1:name   AC/DC
artist:1:genre  Hard Rock
artist:2:name   Slim Dusty
artist:2:genre  Country

The problem here is if the underlying datastore does not support transactions then missing data in a set might occur. However a good end-user application design that understand that each data stored for example, the artist entity are actually multiple values stored, then that would not be a problem. The key here is the application must "understand" that the database in use is a Key-Value stored, much like how DNS registrations are designed with each record is saved individually instead of batch, which will be the usual case since most KV store can't handle batch operations.