This illustration shows two steps required for grabbing the token.
Step 1: Identify True Owner
acct_ny.ny.com
wants ownership of
of the row for the employee whose empno
is 100
.acct_ny.ny.com
site determines the current owner of the row
by querying the headquarters database, which is acct_hq.hq.com
.
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
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.acct_ny.ny.com
site asynchronously updates all other replication
sites to make the owner of the row acct_ny.ny.com
.