1. A method for searching a database of information, the database of information comprising information related to at least one content unit, the information related to the at least one content unit comprising a plurality of stored annotations related to the at least one content unit, wherein a first stored annotation of the plurality of stored annotations comprises a semantic label and content of the first stored annotation, wherein the database stores the semantic label for the first stored annotation in a first table and stores the content of the first stored annotation in at least one second table different from the first table, the method comprising: receiving a query for searching the database; determining at least one query annotation related to the query, the at least one query annotation comprising a first query annotation, wherein determining the first query annotation comprises determining a semantic label for the first query annotation and determining content of the first query annotation; searching the database based at least in part on the first query annotation, the searching comprising searching the first table of the database using the semantic label for the first query annotation and searching the at least one second table of the database using the content of the first query annotation; and receiving, in response to the search, information regarding at least one matching content unit to which at least one stored annotation relates, the at least one stored annotation comprising an annotation having a semantic label and content matching the semantic label and content of the first query annotation related to the query.