Example implementations relate to processing a query of a database and a data stream. For example, a computing device may include a processor. The processor may receive a query associated with at least one of a database and a buffer storing streamed data from a data stream. The database may store database data previously stored in the buffer. The processor may identify a range associated with the query and generate a set of sub-queries including at least one of a buffer sub-query if the range is associated with the streamed data in the buffer and a database sub-query if the range is associated with the database data in the database. The processor may process the set of sub-queries and provide a query result of the query, where the query result is a combination of sub-query results of the set of sub-queries.