V$LOGMNR_CONTENTS确定唯一行

最新推荐文章于 2023-03-22 16:05:39 发布

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最新推荐文章于 2023-03-22 16:05:39 发布

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分类专栏： logmnr

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V$LOGMNR_CONTENTS确定唯一行

Select
 SCN,start_scn,commit_scn,xid,rs_id,ssn,csf,
 timestamp "Time Stamp",
 
 sql_redo "SQL Redo",session#
 
From V$LOGMNR_CONTENTS t where session#=863 and serial#=3 
Order by t.scn,t.rs_id,t.ssn

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1、rs_id,ssn确定唯一行，Order by t.scn,t.rs_id,t.ssn基本可以确定sql在redo里的执行顺序

2、csf是sql_redo过长（超过4000字节）其值就为1，从第一个csf=1到最后一个cdf=0代表完整的一行。
备注：rs_id：XX1.XX2.XX3

xx1：16进制的归档日志ID
xx2：当前行的block id
xx3：16进制的当前行block id的偏移量
ssn：SQL sequence number

在这里插入图片描述

附oracle doc

RS_ID  	VARCHAR2(32)	
Record set ID. The tuple (RS_ID, SSN) together uniquely identifies a logical row change. This will usually mean one row from V$LOGMNR_CONTENTS, 
but could be more than one row if a single SQL statement for either the Redo or Undo would be too large to fit within the respective columns SQL_UNDO or SQL_REDO. 
RS_ID uniquely identifies the redo record that generated the row.

SSN	NUMBER	SQL sequence number. Used in conjunction with RS_ID, this uniquely identifies a logical row change, shown as one or more rows from the V$LOGMNR_CONTENTS view.

CSF	NUMBER	Continuation SQL flag. Possible values are:
0 - Indicates SQL_REDO and SQL_UNDO is contained within the same row

1 - Indicates that either SQL_REDO or SQL_UNDO is greater than 4000 bytes in size and is continued in the next row returned by the view