oracle SQL性能分析

1.查看消耗資源最多的 SQL：
select hash_value, executions, buffer_gets, disk_reads, parse_calls
from v$sqlarea
where buffer_gets > 10000000 or disk_reads > 1000000
order by buffer_gets + 100 * disk_reads desc ;
2. 查看某條 SQL 語句的資源消耗：
select hash_value, buffer_gets, disk_reads, executions, parse_calls
from v$sqlarea
where hash_value = 27762888 and address = hextoraw('cbndcdo6j');
3.查找前10條性能差的sql語句
select * from
(select parsing_user_id,executions,sorts,command_type,disk_reads,sql_text from v$sqlarea order by disk_reads desc )
where rownum<10 ;
說明:
EXECUTIONS表示同一條SQL語句一共執行了多少次，SORTS表示排序的次數，DISK_READS表示物理讀的數量。