@Override
  public Pattern<CorrelatedJoinNode> getPattern() {
    return PATTERN;
  }
Tries to decorrelate subquery and rewrite it using normal join. Decorrelated predicates are part
of join condition.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/relational/planner/iterative/rule/TransformCorrelatedJoinToJoin.java