title: How to get ALL users' posts' tags (include answer's tags) in the Stack Exchange Data Explorer?
body: <p>I use a query in the <a href="https://data.stackexchange.com/stackoverflow/queries?order_by=popular" rel="nofollow noreferrer">Stack Exchange Data Explorer</a> (SEDE).</p>
  
  <p>This is <a href="https://data.stackexchange.com/stackoverflow/query/901423?UserId=331508" rel="nofollow noreferrer">my query</a>:</p>
  
  <pre><code>SELECT A.Id
         , A.PostTypeId
         , A.Title
         , A.Body
         , A.ParentId
         , A.Tags
         , A.CreationDate
  FROM   posts A
         LEFT JOIN users U
                ON A.OwnerUserId = U.id
  WHERE  U.Id = ##UserId##
         AND A.PostTypeId = 1
  UNION
  SELECT A.Id
         , A.PostTypeId
         , A.Title
         , A.Body
         , A.ParentId
         , B.Tags
         , A.CreationDate
  FROM   posts A
         LEFT JOIN users U
                ON A.OwnerUserId = U.id
         RIGHT JOIN posts B
                 ON A.ParentId = B.Id
  WHERE  U.Id = ##UserId##
         AND A.PostTypeId = 2
  </code></pre>
  
  <p>In the code above, posts in Stack Overflow have 2 types: question and answer. Questions(<code>PostTypeId</code> is 1 in database schema) have the tags, but the answers(<code>PostTypeId</code> is 2 in database schema) do not have the tags.
  Answers belong to questions through the <code>ParentId</code>.</p>
  
  <p>But the efficiency of the my query above is too low, I only can get some (using user id) posts' tags.</p>
  
  <p>How can I get all users' posts' tags within the SEDE time out?</p>