17. A system for storing data, the system comprising: one or more storage devices; at least one processor; and a storage module comprising a non-transitory computer-readable medium storing instructions that, when executed, cause the system to: store a first version of a document in a first structure on a first storage device; receive an updated version of the document; identify one or more frequently updated portions of the document; store on the first storage device the one or more frequently updated portions of the document, in a second structure separate from the first structure; receive a request for the document; retrieve the first version of the document from the first structure and the frequently updated portions of the document from the second structure; merge the updated portions with the first version to obtain a merged version of the document, by writing the updated portions to the first version of the document; and return the merged version of the document in response to the request.
17. A system for storing data, the system comprising: one or more storage devices; at least one processor; and a storage module comprising a non-transitory computer-readable medium storing instructions that, when executed, cause the system to: store a first version of a document in a first structure on a first storage device; receive an updated version of the document; identify one or more frequently updated portions of the document; store on the first storage device the one or more frequently updated portions of the document, in a second structure separate from the first structure; receive a request for the document; retrieve the first version of the document from the first structure and the frequently updated portions of the document from the second structure; merge the updated portions with the first version to obtain a merged version of the document, by writing the updated portions to the first version of the document; and return the merged version of the document in response to the request. 19. The system of claim 17 , wherein: the first version of the document is a blob; and the second structure is stored proximate to the first structure.