ASTERIXDB-1322: fix variable visitors for SubplanOperator.

- Simplified the implementation of OperatorPropertiesUtil;
- Fixed PushProjectDownRule to not introduce project operator
  into a subplan to project outer variables.

Change-Id: I53ee1e27b41c9c80d51a7e1baf058d97338c18a9
Reviewed-on: https://asterix-gerrit.ics.uci.edu/662
Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Reviewed-by: Till Westmann <tillw@apache.org>
5 files changed
tree: 374c8ac7296d108ee8fc47cfb836b848e89ae076
  1. .gitignore
  2. DISCLAIMER
  3. LICENSE
  4. NOTICE
  5. algebricks/
  6. hyracks/
  7. pom.xml
  8. src/