I've been concerning this problem for a few months.
The "transaction logs" is actually the history events of an entity.
With an initial state is offer, the current state of an entity can be
calculated with the help of history events.
So if you want to know a property of an entity currently, these
Yes, I thought the same... Now, encouraged by Dave message ;-) some links:
http://martinfowler.com/eaaDev/EventSourcing.html
Dave mentioned CQRS, some post about Events, Event Sourcing AND CQRS:
http://thinkbeforecoding.com/tag/CQRS
CQRS (Command Query Responsibility Separation) is a big topic, po
This sounds a lot like Event Sourcing to me. (often coupled with CQRS).
Which, I think, is similar to what datomic is doing, where:
- datom => event
- transactor => event store
- peer => query model
There are a number of presentations, blogs available on this if you haven't
seen
Jonas,
Definitely inspired by the ideas in Datomic.
My question was partially: "how can I implement the core immutability
semantics of Datomic in plain Clojure?".
(Say, hypothetically, that I need a Clojure datastore with flexible
schema and immutability semantics but cannot actually use Datomic f
It is not totally clear in your post how you want to keep the data?
Is it in memory (with a transactional log somewhere)?
If it is the case, you can do better than reducing the whole data set
when executing a query:
you can keep a cache of query results, or indexed data and maintain
it, while still
On Tuesday, June 5, 2012 3:59:39 AM UTC+3, Kevin Lynagh wrote:
>
> Has anyone seen or implemented a CRUD application in Clojure using a
> database of immutable facts?
>
> For instance, a traditional database table supporting a todo-list
> application has columns
>
> user_id, task_id, task
Has anyone seen or implemented a CRUD application in Clojure using a
database of immutable facts?
For instance, a traditional database table supporting a todo-list
application has columns
user_id, task_id, task_description, is_done
A new row is created when a user adds a task.
Then that row
