Re: Lock

From: Jonathan Lewis <>
Date: Mon, 12 Mar 2012 12:35:42 -0000
Message-ID: <5C01B545606748CFA1E0D27DFAD01EA9_at_Primary>

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 transaction


Jonathan Lewis
Oracle Core (Apress 2011)

  • Original Message ----- From: "Paul Harrison" <> To: <> 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?




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-- Received on Mon Mar 12 2012 - 07:35:42 CDT

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