[teiid-issues] [JBoss JIRA] (TEIID-784) Enhance distinct set op processing

Enhance distinct set op processing ---------------------------------- Key: TEIID-784 URL: https://issues.jboss.org/browse/TEIID-784 Project: Teiid Issue Type: Feature Request Components: Query Engine Reporter: Steven Hawkins Priority: Minor The sort operation should be able to pushed for each set op child (distinct is already eligible for pushing, but typically won't be because there's no order by). Also for union the sorted children should be fed directly into the second phase of sorting. All of this relies on the connector guaranteeing null ordering (TEIID-715 should be repurposed to cover the language enhancement of nulls first|last)