16. A data storage system for storing at least one file generated by a distributed application in a parallel computing system, wherein said file comprises a plurality of sub-files, comprising: a hardware processing device for obtaining a user specification of semantic information related to said file; determining semantically meaningful sub-file boundaries for said plurality of sub-files based on said semantic information; and for providing said semantic information as a data structure description to a data formatting library write function, wherein said semantic information is dependent upon a content of said file; and a memory for storing said semantic information related to said file with additional metadata related to said file and with one or more of said sub-files using said determined semantically meaningful sub-file boundaries in one or more storage nodes of said parallel computing system.
19. The data storage system of claim 16 , wherein said processing device is further configured to process a query using said semantic information.