Re: Lock

  • From: "Jonathan Lewis" <jonathan@xxxxxxxxxxxxxxxxxx>
  • To: <oracle-l@xxxxxxxxxxxxx>
  • Date: Mon, 12 Mar 2012 12:35:42 -0000

Ambiguous question, really.

Each row will have its lock byte set.
Each table block involved will have one ITL entry used to identify the 
locking transaction
There will be a TM lock (mode 3, id1 = table's object_id) displayed in 
v$lock to show that there is an active transaction modifying the table.
There will be a TX lock displayed in v$lock which will report the 
transaction table entry from the undo segment header being used by the 


Jonathan Lewis
Oracle Core (Apress 2011)

----- Original Message ----- 
From: "Paul Harrison" <cure@xxxxxxxxxxxxx>
To: <oracle-l@xxxxxxxxxxxxx>
Sent: Saturday, March 10, 2012 4:56 PM
Subject: Lock


I have a table with four rows. I issue the sql statement: update table set
name = 'test';  this will update 4 rows. Will Oracle create 4 locks one for
each row or 1 lock for the 4 rows?




No virus found in this message.
Checked by AVG -
Version: 2012.0.1913 / Virus Database: 2114/4861 - Release Date: 03/09/12


  • References:
    • Lock
      • From: Paul Harrison

Other related posts: