1. A system, comprising: a computer processor; and a memory containing a program that, when executed on the computer processor, performs an operation comprising: receiving a query for processing by a natural language processing (NLP) system; identifying a data source related to the query by associating one or more elements of the query to the data source; upon determining that the related data source is not in a corpus of the NLP system, ingesting the related data source into the corpus; and upon determining that the related data source is in the corpus of the NLP system: determining a time-sensitivity value associated with the query indicating a degree to which an accurate answer to the query is dependent on a staleness of the related data source, and upon determining that the time-sensitivity value satisfies a staleness threshold, re-ingesting the related data source into the corpus.