Appengine Datastore Advantages

 

I have used sql databases a fair bit and can see a lot of benefit in normalised databases that can be joined and searched and relationships built in them.

What are the advantages to the sort of 'object database' that google has in Appengine's datastore?

GAE's BigTable datastore is not object-oriented or even object-relational. It has more in common with a Hashmap than with a standard relational database like MySQL or Oracle. The main advantage is scalability and a tighter guarantee on the amount of time a query will take (sort of like CPU time). The scalability comes from the way records are distributed, if you setup your keys correctly then the data associated with those keys will be closer together physically (the data is distributed so there is no single point of failure).

As many NoSQL databases The main advantage of the Datastore is the flexibility nevertheless the programmer must forget everything about traditional SQL databases. see this article in techrepublic.com about NoSQl databases

  • Data Model flexibility. The programmer doesn't have to worry about map the object model to relational model, just put your Entities in the Datastore.
  • Object relationship flexibility. The datastore supports multiple values for one single property, which let you stablish an 1-N relationship just like in the Object Oriented programming; Ie: inserting a List as a value of one property.

    • The rest of advantages/disadvantages comes from the PaaS (Platform as a service) model, wich means you only worry about write well code and google cares about the infrastructure and scalability. see PaaS in wikipedia

    Technically it's a lot easier to program since the datastore is bundled with the SDK and easier to share source code and collaborate since you're getting all components from the same vendor rather than patching together an RDMS, a scripting engine and hosting.

    Economically, the costeffectiveness GAE ha is a huge advantage since you only pay for what you use. With other services and other hosting you pay like a subscriber while with the model GAE has you pay per quota.

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