CreateQuery merge_tree_pk (children 3)
 Identifier merge_tree_pk
 Columns definition (children 1)
  ExpressionList (children 2)
   ColumnDeclaration key (children 1)
    DataType UInt64
   ColumnDeclaration value (children 1)
    DataType String
 Storage definition (children 2)
  Function ReplacingMergeTree (children 1)
   ExpressionList
  Identifier key
