I'm looking at PGA Memory Usage Details in OEM. It shows under executions up to 1mb almost all Optimal executions. By the time it gets to the 32mb - 64 mb, most are multipass executions with some one pass executions. I've got a PGA aggregate target of 1536. Maximum PGA Allocated has been 731. Should the multipass executions be of concern and if so, what should be done?