Microsoft Azure DocumentDB vs Azure Table Storage

Question

For several recent years, Microsoft offers a "NoSQL" key/value storage, called "Table Storage" (http://azure.microsoft.com/en-us/documentation/articles/storage-dotnet-how-to-use-tables/)

Table Storage offers a high performance, scalability (via partitioning) and relatively low cost. A primary drawback of Tables that only Partition and Row keys can be indexed - so making queries on values is very inefficient.

Recently Microsoft announced a new "NoSQL" service, called "DocumentDB" (http://azure.microsoft.com/en-us/documentation/services/documentdb/)

Instead of storing a list of properties (like Tables do), DocumentDB stores JSON objects. The whole object being indexed - so efficient queries may be created based on every property and any nested property of stored objects.

Microsoft says that DocumentDB provides high performance and scalability as well.

If that's so - why anyone would use Table Storage over DocumentDB? It sounds like DocumentDB provides the same functionality as Tables, but with additional capabilities such as the ability to index anything.

I will glad if someone could make a comparison between DocumentDB and Table Storage, highlighting cons and pros of each one.

Answer 1

Both are NoSQL technologies, but they are massively different. Azure Tables is a simple Key/Value store and does not support complex functionality like complex queries (most of them will require a full partition/table scan anyway, which will kill your performance and your cost savings), custom indexing (indexing is based on PartitionKey and RowKey only, you currently can't index on any other entity property and searching for anything other than PartitionKey/RowKey combination will require a partition/table scan), or stored procedures. You also can't batch read requests for multiple entities (through batch write requests are supported if all the entities belong to the same partition). For a real-life application of Azure Tables, see HERE.

If your data needs (particularly around querying them) are simple (like in the example above), then Azure Tables provide what you need, you might end up using that in favor of DocDB due to pricing, performance and storage capacity. For example, Azure Tables performance target is 20.000 operations per second. Trying to get that same level of performance on DocDB will have a significantly higher service cost for you. Also, Azure tables are limited by the capacity of your Azure storage account (500TB), whereas DocDB storage is limited by the capacity units you buy.