PostgreSQL中的CTE尾递归吗？

Question

我想知道postgresql中的递归查询，例如下面的查询是否是尾递归的？

WITH RECURSIVE category_tree(id, name, path) AS (
  SELECT id, name, ARRAY[id]
  FROM categories
  WHERE parent_id IS NULL
  UNION ALL
  SELECT categories.id, categories.name, path || categories.id
  FROM category_tree
  JOIN categories ON categories.parent_id=category_tree.id
  WHERE NOT categories.id = ANY(path)
)
SELECT * 
FROM category_tree 
ORDER BY path;