Providing flexibility in scheduling control for an extract, transfer, and load ("ETL") scheduler in a data warehouse system, including extracting from a computer memory of the data warehouse system a dependent condition for a scheduled ETL processing step of the ETL scheduler, extracting from computer memory related ETL data for the dependent condition, determining whether the ETL data satisfies the dependent condition, and executing the scheduled step if the ETL data satisfies the dependent condition. A sub-scheduler typically is implemented as an interface between an ETL scheduler and external programs without modification of the ETL scheduler. In typical embodiments, an ETL scheduler includes a multiplicity of scheduled ETL processing steps, and computer memory of a data warehouse system includes dependent conditions for at least one of the scheduled ETL processing steps and ETL data related to at least one dependent condition.