这个查询可以根据初始化参数设置和软件版本，查找出默认情况下会以全表扫描方式访问的表。
/*Auth:chensq#itpub.net
Date:2005-07-29 17:43
*/
select segment_name,bytes from dba_segments a,dba_tables b
where bytes<(
case when (select 0 from dual where not exists (select value from v$parameter where name like '%small_table_%'))=0 then
--parameter _small_table_threshold is not seted
(select case when (select SUBSTR(BANNER,6,1) from v$version where banner like 'CORE%')<9 then --lower than 9i
(select value*.02 from v$parameter where name='db_cache_size')
else (bytes/a.blocks)*20--above 9i
end from dual)
else
(select to_number(value) from v$parameter where name like '%small_table_%')
end
)--_small_table_threshold
and a.segment_name=b.table_name
这个查询可以根据初始化参数设置和软件版本，查找出默认情况下会以全表扫描方式访问的表。