Explain EXPLAIN (children 2)
 Set
 SelectWithUnionQuery (children 1)
  ExpressionList (children 2)
   SelectQuery (children 4)
    ExpressionList (children 1)
     Asterisk
    TablesInSelectQuery (children 2)
     TablesInSelectQueryElement (children 1)
      TableExpression (children 1)
       TableIdentifier t1
     TablesInSelectQueryElement (children 2)
      TableExpression (children 1)
       TableIdentifier t2
      TableJoin (children 1)
       ExpressionList (children 1)
        Identifier x
    Function or (children 1)
     ExpressionList (children 2)
      Function greater (children 1)
       ExpressionList (children 2)
        Identifier t1.x
        Literal UInt64_2
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier t2.y
        Literal \'a\'
    Literal UInt64_10
   SelectQuery (children 4)
    ExpressionList (children 1)
     Asterisk
    TablesInSelectQuery (children 2)
     TablesInSelectQueryElement (children 1)
      TableExpression (children 1)
       TableIdentifier t2
     TablesInSelectQueryElement (children 2)
      TableExpression (children 1)
       TableIdentifier t1
      TableJoin (children 1)
       ExpressionList (children 1)
        Identifier x
    Function or (children 1)
     ExpressionList (children 2)
      Function less (children 1)
       ExpressionList (children 2)
        Identifier t2.x
        Literal UInt64_2
      Function equals (children 1)
       ExpressionList (children 2)
        Identifier t1.y
        Literal \'c\'
    Literal UInt64_10
