Like a cat on Hot tin roof changing sdu size

Introduction

On one of the projects there is a performance dip between Midnight and 05:00 and I have been asked to investigate the environment.  The Oracle database I am working with is a 920.6 32 bit version on HP UNIX.  I have used Stats pack as tool to do analyses. These stats packs are running in 15 minutes intervals in the database. During the intervals at night the top wait events are very often:

Event                                               Waits    Time (s) Ela Time
-------------------------------------------- ------------ ----------- --------
SQL*Net more data to client                        77,119          74    31.11
CPU time                                                           63    26.36

 

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