Generating execution tracking rows during query execution via a database system

A database system is operable to generate query output based on executing a plurality of operators of a query operator execution flow for a query. Executing each operator can include generating a set of output query rows based on processing a set of input query rows, maintaining execution tracking data for the each operator that includes at least one counter tracking at least one event type, and generating a set of execution tracking rows based on sampling the execution tracking data. The query output includes a final set of rows corresponding to a query resultant and a final set of execution tracking rows generated by at least one final operator based on an aggregation of a plurality of sets of execution tracking rows generated by the plurality of operators.