A graphical user interface allows a customer to specify delimiters and/or patterns that occur in event data and indicate the presence of a particular field. The graphical user interface applies a customer's delimiter specifications directly to event data and displays the resulting event data in real time. Delimiter specifications may be saved as configuration settings and systems in a distributed setting may use the delimiter specifications to extract field values as the systems process raw data into event data. Extracted field values are used to accelerate search queries that a system receives.