Number of physical writes of temporary pages: <count>
When temporary data pages are generated to build (buffer) sets of results (in JOINS or ORDER BY statements, for example), the data cache is not large enough for the temporary pages, and they have to be swapped into the data area. However, these pages must be exported out of the data area again for the further processing of the SQL statement.
Find the statement that causes these large amounts of (buffer) results to be created, and check the access strategies for this statement.
For information on creating optimized SQL statements, see the SQL Optimizer documentation.