CreateQuery t1 (children 3)
 Identifier t1
 Columns definition (children 1)
  ExpressionList (children 3)
   ColumnDeclaration key1 (children 1)
    DataType UInt64
   ColumnDeclaration key2 (children 1)
    DataType UInt64
   ColumnDeclaration key3 (children 1)
    DataType UInt64
 Storage definition (children 2)
  Function MergeTree
  Function tuple (children 1)
   ExpressionList
