1. A method for processing log data, comprising: receiving log data that comprises a plurality of events, wherein an event includes a set of fields, and wherein a field stores a value; and for each event in the plurality of events: storing the event in a set of buffers, wherein each field value of the event is stored in a different buffer; identifying a first value stored in a first field of the event; identifying a first minimum value that indicates a minimum value of the first field of all of the events stored in the buffers, wherein the first minimum value is stored in a metadata structure that comprises information about contents of the buffers; determining whether the first minimum value exceeds the first value; and responsive to determining that the first minimum value exceeds the first value, updating the metadata structure by replacing the first minimum value with the first value.