CreateQuery small (children 3)
 Identifier small
 Columns definition (children 1)
  ExpressionList (children 2)
   ColumnDeclaration dt (children 1)
    DataType DateTime
   ColumnDeclaration user_email (children 1)
    DataType LowCardinality (children 1)
     ExpressionList (children 1)
      DataType Nullable (children 1)
       ExpressionList (children 1)
        DataType String
 Storage definition (children 3)
  Function MergeTree
  Function tuple (children 1)
   ExpressionList (children 2)
    Identifier dt
    Identifier user_email
  Set
