User's Manual

♦ The subscription expression in this example returns a single value.
Subqueries returning multiple values can also be used. The value of the
subscription expression must the value after the UPDATE.
In this case, the only subscriber to the row is the new sales representative.
In “Sharing rows among several subscriptions” on page 112, we see cases
where there are existing as well as new subscribers.
Information in the
transaction log
Here we describe the information placed in the transaction log.
Understanding this helps in designing efficient publications.
♦ Assume the following data:
• SalesRep table
rep_key Name
rep1 Ann
rep2 Marc
• Customer table
cust_key name rep_key
cust1 Sybase rep1
cust2 ASA rep2
• Contact table
contact_key name cust_key
contact1 David cust1
contact2 Stefanie cust2
♦ Now apply the following territory realignment Update statement
UPDATE Customer
SET rep_key = ’rep2’
WHERE cust_key = ’cust1’
The transaction log would contain two entries arising from this statement:
one for the BEFORE trigger on the Contact table, and one for the actual
UPDATE to the Customer table.
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