Explain EXPLAIN (children 2)
 Set
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 3)
    ExpressionList (children 3)
     Identifier t1.id
     Identifier t1.value
     Identifier t2.value
    TablesInSelectQuery (children 2)
     TablesInSelectQueryElement (children 1)
      TableExpression (children 1)
       TableIdentifier test_table (alias t1)
     TablesInSelectQueryElement (children 2)
      TableExpression (children 1)
       TableIdentifier test_table_join (alias t2)
      TableJoin (children 1)
       Function equals (children 1)
        ExpressionList (children 2)
         Identifier t1.id
         Identifier t2.id
    Function equals (children 1)
     ExpressionList (children 2)
      Identifier t1.id
      Literal UInt64_0
