A tokenspace repository stores documents as a sequence of tokens. A first version of a document is stored in the repository, within an accessible range of the repository. When a second version of the document is received, the second version is also stored in the repository and the accessible range of the repository is modified to include both the first version and the second version of the document. Then the first version of the document is invalidated. Queries are executed against the repository in a plurality of threads without interruption during the operations of receiving the second version of the document, storing the second version of the document in the repository, modifying the accessible range of the repository, and invalidating the first version of the document.