1. A personal content item searching system comprising one or more hardware processors configured to: generate a base index of content items hosted by an online content management service, the content items associated with a particular user account, of a plurality of user accounts, held with the service; transmit, over a network, to a user computer associated with the particular user account, the generated base index; detect a change to at least one of the content items, the change resulting in a new version of the at least one content item; determine an identifier of a particular content item namespace to which the at least one content item belongs, the particular content item namespace being one of a plurality of content item namespaces containing content items hosted by the online content management service, the particular content item namespace associated with the particular user account; generate an index mutation reflecting the change to the at least one content item, the index mutation comprising one or more tokens to use to index the at least one content item and/or one or more tokens to not use to index the at least one content item, and comprising the identifier of the particular content item namespace; store the index mutation in an index mutation journal; identify the index mutation in the index mutation journal as being for the user computer, based, at least in part, on the identifier of the particular content item namespace of the index mutation; and transmit to the user computer, over the network, the one or more tokens to use to index the at least one content item and/or the one or more tokens to not use to index the at least one content item of the generated index mutation.