--使用dbms_workload_repository.drop_snapshot_range可以删除历史数据，怎奈太慢了，半个小时完全没有反映。通过v$session看到执行的SQL是delete，这种做法无法降低高水位线。
SQL> select min(snap_id),max(snap_id) from dba_hist_snapshot;
MIN(SNAP_ID) MAX(SNAP_ID)
------------ ------------
SQL> select min(snap_id),max(snap_id) from dba_hist_active_sess_history;
MIN(SNAP_ID) MAX(SNAP_ID)
------------ ------------
1 36768
SQL> begin
dbms_workload_repository.drop_snapshot_range(
low_snap_id => 1,
high_snap_id => 36768,
dbid => 1148453265);
end;
--手工生成truncate，需要在SYS下执行
select distinct 'truncate table '||segment_name||';',s.bytes/1024/1024
from dba_segments s
where s.segment_name like 'WRH$%'
and segment_type in ('TABLE PARTITION', 'TABLE')
and s.bytes/1024/1024>100
order by s.bytes/1024/1024/1024 desc;
--执行完成后，看效果
SQL> SELECT Upper(F.TABLESPACE_NAME) "表空间名",
D.TOT_GROOTTE_MB "表空间大小(M)",
D.TOT_GROOTTE_MB - F.TOTAL_BYTES "已使用空间(M)",
To_char(Round(( D.TOT_GROOTTE_MB - F.TOTAL_BYTES ) / D.TOT_GROOTTE_MB * 100, 2), '990.99')
|| '%' "使用比",
F.TOTAL_BYTES "空闲空间(M)",
F.MAX_BYTES "最大块(M)"
FROM (SELECT TABLESPACE_NAME,
Round(Sum(BYTES) / ( 1024 * 1024 ), 2) TOTAL_BYTES,
Round(Max(BYTES) / ( 1024 * 1024 ), 2) MAX_BYTES
FROM SYS.DBA_FREE_SPACE
GROUP BY TABLESPACE_NAME) F,
(SELECT DD.TABLESPACE_NAME,
Round(Sum(DD.BYTES) / ( 1024 * 1024 ), 2) TOT_GROOTTE_MB
FROM SYS.DBA_DATA_FILES DD
GROUP BY DD.TABLESPACE_NAME) D
WHERE D.TABLESPACE_NAME = F.TABLESPACE_NAME
and D.tablespace_name = 'SYSAUX';
表空间名 表空间大小(M) 已使用空间(M) 使用比 空闲空间(M) 最大块(M)
--------- ------------- ------------- -------- ----------- ----------
SYSAUX 37887.98 9132.67 24.10% 28755.31 544