This illustration shows the two steps required for grabbing the token.
Step 1: Identify True Owner
The replication site acct_ny.ny.com
wants ownership of the row for the employee whose empno
is 100
.
The acct_ny.ny.com
site determines the current owner of the row by querying the headquarters database, which is acct_hq.hq.com
.
The acct_ny.ny.com
site determines that current owner for the row is the site acct_sf.sf.com
.
Step 2: Grab Ownership and Broadcast Change
The replication site acct_ny.ny.com
locks the row locally and synchronously updates both the acct_ny.ny.com
site and the acct_sf.sf.com
site, making the owner of the row acct_ny.ny.com
at both sites.
The acct_ny.ny.com
site asynchronously updates all other replication sites to make the owner of the row acct_ny.ny.com
.