CreateQuery src (children 3)
 Identifier src
 Columns definition (children 1)
  ExpressionList (children 3)
   ColumnDeclaration event_time (children 1)
    DataType DateTime
   ColumnDeclaration key (children 1)
    DataType UInt64
   ColumnDeclaration value (children 1)
    DataType Int64
 Storage definition (children 2)
  Function MergeTree (children 1)
   ExpressionList
  Function tuple (children 1)
   ExpressionList (children 2)
    Identifier event_time
    Identifier key
