Example implementations relate to a database and a data stream query. 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, where the database stores database data previously stored in the buffer. The processor may identify at least one postponed command relevant to the query, the at least one postponed command being associated with at least one of the database data and the streamed data. The processor may generate a modified query based on the query and the at least one postponed command, the modified query being a modification of the query to account for the at least one postponed command. The processor may process the modified query and provide a query result of the query based on the modified query being processed.