SYSTEM表空间使用率高

数据库监控告警,SYSTEM表空间使用率很高.检查发现LOB字段使用了很大的空间,定位到LOB字段属于SYS_EXPORT_FULL_%表,参考(Doc ID 1626201.1)步骤处理后,表空间使用率大幅下降.

查询使用空间比较多的对象

set linesize 500 pagesize 10
col owner for a20
col segment_name for a30
select owner,segment_name,round(sum(bytes/1024/1024/1024),2) GB from dba_segments where tablespace_name='SYSTEM' group by owner,segment_name order by 3;
OWNER                SEGMENT_NAME                           GB
-------------------- ------------------------------ ----------
SYS                  SYS_LOB0001301589C00045$$            6.19
SYS                  SYS_LOB0011275889C00045$$            6.46

检查LOB对象属于什么对象

select owner,table_name from dba_lobs where SEGMENT_NAME='SYS_LOB0011275889C00045$$';
OWNER                          TABLE_NAME
------------------------------ ------------------------------
SYS                            SYS_EXPORT_FULL_08

确定dump作业没有在运行

SET lines 200
COL owner_name FORMAT a10;
COL job_name FORMAT a20
COL state FORMAT a12
COL operation LIKE state
COL job_mode LIKE state
COL owner.object for a50
SELECT owner_name, job_name, rtrim(operation) "OPERATION",
rtrim(job_mode) "JOB_MODE", state, attached_sessions
FROM dba_datapump_jobs
WHERE job_name NOT LIKE 'BIN$%'
ORDER BY 1,2;
OWNER_NAME                     JOB_NAME                       OPERATION  JOB_MODE                       STATE                          ATTACHED_SESSIONS
------------------------------ ------------------------------ ---------- ------------------------------ ------------------------------ -----------------
SYS                            SYS_EXPORT_FULL_01             EXPORT     FULL                           NOT RUNNING                                    0
SYS                            SYS_EXPORT_FULL_02             EXPORT     FULL                           NOT RUNNING                                    0
SYS                            SYS_EXPORT_FULL_03             EXPORT     FULL                           NOT RUNNING                                    0
SYS                            SYS_EXPORT_FULL_04             EXPORT     FULL                           NOT RUNNING                                    0
SYS                            SYS_EXPORT_FULL_05             EXPORT     FULL                           NOT RUNNING                                    0
SYS                            SYS_EXPORT_FULL_06             EXPORT     FULL                           NOT RUNNING                                    0
SYS                            SYS_EXPORT_FULL_07             EXPORT     FULL                           NOT RUNNING                                    0
SYS                            SYS_EXPORT_FULL_08             EXPORT     FULL                           NOT RUNNING                                    0
SYS                            SYS_EXPORT_FULL_09             EXPORT     FULL                           NOT RUNNING                                    0

OWNER_NAME                     JOB_NAME                       OPERATION  JOB_MODE                       STATE                          ATTACHED_SESSIONS
------------------------------ ------------------------------ ---------- ------------------------------ ------------------------------ -----------------
SYS                            SYS_EXPORT_FULL_10             EXPORT     FULL                           NOT RUNNING                                    0
SYS                            SYS_EXPORT_FULL_11             EXPORT     FULL                           NOT RUNNING                                    0
SYS                            SYS_EXPORT_FULL_12             EXPORT     FULL                           NOT RUNNING                                    0
SYS                            SYS_EXPORT_FULL_13             EXPORT     FULL                           NOT RUNNING                                    0
SYS                            SYS_EXPORT_SCHEMA_01           EXPORT     SCHEMA                         NOT RUNNING                                    0
SYS                            SYS_EXPORT_SCHEMA_02           EXPORT     SCHEMA                         NOT RUNNING                                    0

SELECT o.status, o.object_id, o.object_type,
o.owner||'.'||object_name "OWNER.OBJECT"
FROM dba_objects o, dba_datapump_jobs j
WHERE o.owner=j.owner_name AND o.object_name=j.job_name
AND j.job_name NOT LIKE 'BIN$%' ORDER BY 4,2;
STATUS   OBJECT_ID OBJECT_TYPE               OWNER.OBJECT
------- ---------- ------------------------- -------------------------------------------
VALID      9766998 TABLE                     SYS.SYS_EXPORT_FULL_01
VALID      9865781 TABLE                     SYS.SYS_EXPORT_FULL_02
VALID      9875786 TABLE                     SYS.SYS_EXPORT_FULL_03
VALID     11162854 TABLE                     SYS.SYS_EXPORT_FULL_04
VALID     11164797 TABLE                     SYS.SYS_EXPORT_FULL_05
VALID     11249730 TABLE                     SYS.SYS_EXPORT_FULL_06
VALID     11273872 TABLE                     SYS.SYS_EXPORT_FULL_07
VALID     11275889 TABLE                     SYS.SYS_EXPORT_FULL_08
VALID     11277903 TABLE                     SYS.SYS_EXPORT_FULL_09
VALID     11281930 TABLE                     SYS.SYS_EXPORT_FULL_10
VALID     11304143 TABLE                     SYS.SYS_EXPORT_FULL_11
VALID     11312135 TABLE                     SYS.SYS_EXPORT_FULL_12
VALID     11314148 TABLE                     SYS.SYS_EXPORT_FULL_13
VALID      9374980 TABLE                     SYS.SYS_EXPORT_SCHEMA_01
VALID      9316834 TABLE                     SYS.SYS_EXPORT_SCHEMA_02

生成删除表的命令

SELECT 'DROP TABLE '||o.owner||'.'||object_name||' PURGE;'
FROM dba_objects o, dba_datapump_jobs j
WHERE o.owner=j.owner_name AND o.object_name=j.job_name
AND j.job_name NOT LIKE 'BIN$%';

将表删除后,SYSTEM表空间使用率使用率已经正常.

注意

不要删除正在运行的dump作业的主表,删除后dump作业会异常终止.