Explain EXPLAIN QUERY TREE (children 2)
 Set
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 4)
    ExpressionList (children 1)
     Identifier value1
    TablesInSelectQuery (children 1)
     TablesInSelectQueryElement (children 1)
      TableExpression (children 1)
       TableIdentifier date_t
    Function and (children 1)
     ExpressionList (children 2)
      Function equals (children 1)
       ExpressionList (children 2)
        Function toYYYYMM (children 1)
         ExpressionList (children 1)
          Identifier date1
        Literal UInt64_199203
      Function and (children 1)
       ExpressionList (children 2)
        Function greaterOrEquals (children 1)
         ExpressionList (children 2)
          Identifier id
          Literal UInt64_1
        Function lessOrEquals (children 1)
         ExpressionList (children 2)
          Identifier id
          Literal UInt64_3
    Set
