ESRI recommends that Oracle's dynamic sampling capability be used to determine the best execution plan on very dynamic tables, specifically SDE_LOGFILE_DATA tables.
By allowing Oracle to dynamically sample the table upon query execution, the statistical information gathered is accurate for this given moment. If statistics are gathered for these tables, the statistical information may be incorrect for the table at any given time. This influences Oracle's Cost Based Optimizer (CBO) in choosing a suboptimal execution plan.
It is recommended to drop the statistics on the SDE_LOGFILE_DATA tables and lock the empty (uncollected) statistical information using the DBMS_STATS.LOCK_TABLE_STATS procedure.
This only applies to Oracle 10g; Oracle 9i does not have the lock_table_stats procedure.
exec sys.dbms_stats.lock_table_stats('<USER>', 'SDE_LOGFILE_DATA')