Explain EXPLAIN PIPELINE (children 1)
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 3)
    ExpressionList (children 1)
     Asterisk
    TablesInSelectQuery (children 1)
     TablesInSelectQueryElement (children 1)
      TableExpression (children 1)
       TableIdentifier t
    Literal UInt64_100
