CreateQuery event (children 3)
 Identifier event
 Columns definition (children 1)
  ExpressionList (children 3)
   ColumnDeclaration event_time (children 1)
    DataType DateTime
   ColumnDeclaration event_name (children 1)
    DataType String
   ColumnDeclaration user_id (children 1)
    DataType String
 Storage definition (children 2)
  Function MergeTree (children 1)
   ExpressionList
  Function tuple (children 1)
   ExpressionList (children 2)
    Identifier event_time
    Identifier event_name
