1. A method for processing data, comprising: creating, for a first transaction, a pending content item from a committed content item; providing a second transaction read access to the committed content item while providing the first transaction write access to the pending content item; the first transaction committing the pending content item; in response to the first transaction committing the pending content item, flagging the committed content item as deleted; and deferring deletion of the committed content item until the second transaction finishes accessing the committed content item; after the second transaction finishes accessing the committed content item, deleting the committed content item; wherein the method is performed by one or more computing devices.