Re: ITL mechanism

From: vsevolod afanassiev <vsevolod.afanassiev_at_gmail.com>
Date: Thu, 11 Aug 2011 20:19:16 -0700 (PDT)
Message-ID: <4d1b21ea-2bd7-42ca-ad2b-d93bad58398d_at_y8g2000prd.googlegroups.com>

Thanks. Let's say there are 100 rows in a block and 50 got updated by one transaction. Then single ITL entry
should contain information about 50 rows. How do you fit information about 50 rows in 24 bytes?

http://avdeo.com/2008/06/16/interested-transaction-list-itl/ Quote:
This variable portion of the data block contains slots for transactions to put the locking information. When a row in the block is locked for the first time, the transaction places a lock in one of the slots with the rowid of the row that is locked. In other words, the transaction makes it known that it is interested in the row (hence the name “Interested Transaction List”). When the same transaction or another one locks another row, the information is stored in another slot, and so on. Received on Thu Aug 11 2011 - 22:19:16 CDT