OPT_GOAL

Does anyone have any comments on OPT_GOAL We've experimented with setting it to 0 and found it to be detrimental to batch processing jobs. My understanding is that it will influence the optimizer to choose a path that will return the first rows quickly but not necessarily ALL rows quicker than if it had been left at the default of -1. What's it's application? Is anyone using it effectively as an ONCONFIG parameter, or is everyone using it as an environment variable. TIA, Greg.