高水位表检查以及回收高水位

1) 高水位表收集

SELECT NUM_ROWS,AVG_ROW_LEN*NUM_ROWS/1024/1024/0.9 NEED, BLOCKS*8/1024 TRUE,(BLOCKS*8/1024-AVG_ROW_LEN*NUM_ROWS/1024/1024/0.9) RECOVER_MB,TABLE_NAME

FROM dba_tables

WHERE tablespace_name='表空间名' AND BLOCKS*8/1024-AVG_ROW_LEN*NUM_ROWS/1024/1024/0.9>100

AND rownum<11 order by RECOVER_MB desc;

统计信息的脚本：exec dbms_stats.gather_table_stats('user','table_name');

2) 启用表的行转移功能

SQL> alter table '表名' enable row movement ;

3) 压缩高水位线

SQL> alter table '表名' shrink space ;

4) 查看统计信息

SQL> select t.table_name,BLOCKS,EMPTY_BLOCKS,NUM_ROWS

from user_tables t

where table_name = upper('表名');

5) 收集统计信息

SQL> exec dbms_stats.gather_table_stats('sys','表名');

6) 再次查看

SQL> select t.table_name,BLOCKS,EMPTY_BLOCKS,NUM_ROWS

from dba_tables t

where table_name = upper('表名');