INITRANS

select * from v$event_name where name like 'enq: FB%';

select NAME,PARAMETER1,PARAMETER2,PARAMETER3,WAIT_CLASS_ID,DISPLAY_NAME from v$event_name where name like 'enq: FB%';

select TYPE,NAME,ID1_TAG,ID2_TAG,IS_USER,DESCRIPTION from v$lock_type where TYPE='FB';

select session_id, sql_id, event, p1, p1text, p2 "TS#", p3 "Block", wait_time, session_state, time_waited from gv$active_session_history where event like '%FB%'

and sql_id = '<insert_Stmt_SQL_ID_FROM_AWR>'; ------>>>> Replace SQL_ID

  1. If we have multiple sessions doing insert concurrently and more than one session are trying to format the block that may cause the contention.The value on P1 is name|mode , P2 tells the tablespace number, and P3 gives the dba.

SQL> select session_id,SQL_ID,EVENT,P1,P1text,P2,P3,WAIT_TIME,SESSION_STATE,TIME_WAITED from v$active_session_history where event like '%FB%';

SQL> select name from v$tablespace where ts#=P2; ----------->>> P2 value from above

SQL> SELECT dbms_utility.data_block_address_block(p3) "BLOCK", dbms_utility.data_block_address_file(p3) "FILE" from dual; ---->>> P3 Value from Above

-- and --

#1-- Also you can use below ::

SQL> select SID,USERNAME,SQL_ID from v$session where SQL_ID='&SQL_ID';

Enter SQL_IDs

#2-- SQL> select username, event, p1, p2 from v$session_wait where sid =&SID;

Now Enter all the SID separately / one by one for each SQL_ID from (#1).

#3-- SQL> select segment_name,segment_type from dba_extents where file_id = &file_id and &Block_id between block_id and block_id + blocks - 1;

FILE_ID=P1

BLOCK_ID=P2

SQL> alter table <TABLE> INITRANS 10 PCTFREE 40;

SQL> alter index <IND_NAME> rebuild partition <Partition_name> initrans 50 PCTFREE 40;

SQL> alter table <Schema.Table_name> modify default attributes tablespace <TS_NAME> initrans 10;

SQL> ALTER INDEX INDEX_NAME INITRANS 10 ;

  1. Check for Below possible workarounds

* If there is any changes in Tablespace / Table level storage parameters recently

* If you have all the object and partitions in same tablespaces then move them to different tablespaces.

* Undersized storage parameters may cause the issue so please check and increase the value ( ex. PCTFREE and INITRANS etc )

SQL> alter table <TABLE> INITRANS 10 PCTFREE 40;

SQL> alter index <IND_NAME> rebuild partition <Partition_name> initrans 50 PCTFREE 40;

SQL> alter table <Schema.Table_name> modify default attributes tablespace <TS_NAME> initrans 10;

SQL> ALTER INDEX INDEX_NAME INITRANS 10 ;

* If you have large index block split then:

For segments with automatic ASSM, Oracle ignores attempts to change the PCT% setting. If you alter the PCT% setting or changed , then you must subsequently run the DBMS_REPAIR.SEGMENT_FIX_STATUS procedure to implement the new setting on blocks already allocated to the segment.

/* Below will Fix the bitmap status for all the blocks in table for that Schema */

SQL> exec dbms_repair.segment_fix_status('<Table_owner>','<Tab_Name>',dbms_repair.table_object);

-- and --

SQL> exec dbms_repair.segment_fix_status('<index_owner>','<index_name>',sys.dbms_repair.index_object);

SQL> exec dbms_repair.segment_fix_status('<index_owner>','<index_name>',dbms_repair.index_object);

Other possible workarounds:

* Auto allocate extent size or Pre allocate the extents to the segment having a high number of inserts.

* Make room for more extents on the Segments also check AWR and ADDM report for other possible Wait events which affects the IO of Database ( db file sequential read etc..)

* Look for any IO issue that is causing slowdown in formatting the blocks.

* Some time high IO operation like LARGE INDEX BLOCK SPLIT may require more extent allocation and may cause the enq: FB contention.

* Try to avoid multiple sessions doing the insert against one segment. Each session may try to format the block and can trigger the contention.

* It's better to put partition segments into different tablespace

相关推荐
嘟嘟实验室6 小时前
微信小程序xr-frame透明视频实现
微信小程序·ffmpeg·音视频·xr
泰勒朗斯11 小时前
如何编译Opencv +ffmpeg linux 明明安装了ffmpeg但是opencv就是找不到
linux·opencv·ffmpeg
-Mr_X-17 小时前
windows下srs流媒体服务器使用ffmpeg推流
ffmpeg
dvlinker18 小时前
C++开源项目 VLC 源代码的交叉编译以及库的裁剪方法详解
ffmpeg·mingw-w64·msys2·cygwin·开源vlc·vlc编译·vlc裁剪
因我你好久不见1 天前
springboot java ffmpeg 视频压缩、提取视频帧图片、获取视频分辨率
java·spring boot·ffmpeg
cuijiecheng20182 天前
音视频入门基础:MPEG2-TS专题(21)——FFmpeg源码中,获取TS流的视频信息的实现
ffmpeg·音视频
cuijiecheng20182 天前
音视频入门基础:AAC专题(13)——FFmpeg源码中,获取ADTS格式的AAC裸流音频信息的实现
ffmpeg·音视频·aac
流氓也是种气质 _Cookie2 天前
uniapp blob格式转换为video .mp4文件使用ffmpeg工具
ffmpeg·uni-app
网络安全queen2 天前
网络安全-企业环境渗透2-wordpress任意文件读&&FFmpeg任意文件读
安全·web安全·ffmpeg
yerennuo2 天前
FFmpeg库之ffmpeg
qt·ffmpeg