adding doc

Author: zhangbowen-coder

doc/source/whatsnew/v3.0.0.rst

@@ -1018,11 +1018,11 @@ Performance improvements
 - Performance improvement in :meth:`DataFrame.astype` when converting to extension floating dtypes, e.g. "Float64" (:issue:`60066`)
 - Performance improvement in :meth:`DataFrame.stack` when using ``future_stack=True`` and the DataFrame does not have a :class:`MultiIndex` (:issue:`58391`)
 - Performance improvement in :meth:`DataFrame.where` when ``cond`` is a :class:`DataFrame` with many columns (:issue:`61010`)
+- Performance improvement in :meth:`merge` and ``DataFrame.merge``.Now user can use prefixes or both of suffixes and prefixes to differentiate duplicated columns.(:issue:`63014`)
 - Performance improvement in :meth:`to_hdf` avoid unnecessary reopenings of the HDF5 file to speedup data addition to files with a very large number of groups . (:issue:`58248`)
 - Performance improvement in ``DataFrameGroupBy.__len__`` and ``SeriesGroupBy.__len__`` (:issue:`57595`)
 - Performance improvement in indexing operations for string dtypes (:issue:`56997`)
 - Performance improvement in unary methods on a :class:`RangeIndex` returning a :class:`RangeIndex` instead of a :class:`Index` when possible. (:issue:`57825`)
-
 .. ---------------------------------------------------------------------------
 .. _whatsnew_300.bug_fixes: