1. A computer-implemented method for indexing a database, the method comprising: detecting user access of media content source by using a computer, the media content source is stored in a computer readable storage medium; determining media content use preferences based on user actions, wherein the media content use preferences comprise a plurality of user preference models, each user preference model comprising semantically similar keywords that correspond to the user actions, wherein the media content use preferences are further based on keywords extracted from information corresponding to the user actions; automatically collecting, from the media content source, media content referenced by a uniform resource locator (URL) and the URL, wherein the detecting, the determining and the collecting are performed responsive to detecting an idle state; extracting semantic text features from, the media content and the URL, wherein the extracting the semantic text features is determined according to a set of extraction rules, wherein the set of extraction rules comprises at least one rule specifying surrounding text be within a threshold semantic distance from a piece of the media content; determining that the media content is interest to a user based at least in part on semantic similarity between the media content use preferences and the semantic text features, and wherein the media content is determined to be interest to the user if there is semantic similarity between the media content and at least one of the user preference models; responsive to determining that the media content is interest to the user, indexing a media database with the extracted semantic text features; monitoring the user actions to identify patterns of media content use from the user actions; modifying indication of relevancy with respect to ones of pieces of the media content based on the patterns of the media content use; performing an analysis of a text to determine that the user desires to access the media content, wherein the analysis is based at least in part on patterns of previous media content use; in response to performing the analysis, generating search criteria based on linguistic features of the text, identifying, based at least in part on the search criteria, one or more media files that are semantically related to the text from the media database; and presenting information corresponding to the one or more media files to the user.