SimpleDS provides a simple persistence framework for Google AppEngine that gets as little in the way as possible. It is barely a wrapper around Datastore APIs, providing mapping between Entity and Java classes.
AppEngine provides a really powerful service to store persistent data in the cloud, but the provided API to handle it is cumbersome:
- The Datastore API is too much low-level, providing bare persistence of Map-style structures.
- The JDO and JPA APIs are too complex for even the simplest tasks, and hurt performance by adding lots of extra checks designed for relational databases.
- This release includes some great new features:
- Level 1 and 2 cache.
- Background tasks to override the 30 seconds limit in AppEngine.
- Functions, a feature that can be combined with caching to get a performance boost by converting n+1 queries into two queries.
Other minor features have also been implemented, such as:
- Cursor support.
- Newer operators such as