1. A method in a computing system for performing a pipelined search, comprising: (a) receiving a search query specifying a first processing command and a second processing command, the search query indicating that the first processing command precedes the second processing command; (b) accessing a plurality of timestamped events derived from machine data; (c) applying the first processing command to data from the accessed plurality of timestamped events to obtain a first result set; (d) associating, with the first result set, metadata reflecting the type of data that resulted from applying the first processing command to data from the accessed plurality of timestamped events; (e) applying the second processing command to data from the first result set to obtain a second result set; (f) associating with the second result set, metadata reflecting the type of data that resulted from applying the second processing command to data from the first result set; and (g) causing display of both the first and second result sets based on their associated metadata.