Saving the transaction for later propagation

In this excerpt from Create order transaction the presence of the SAVE statement after the local changes specifies the later propagation of the local updates to the master database.

-- save the statements for later propagation to master
SAVE CALL INSERT_ORDER(...) ;
SAVE CALL UPDATE_CUSTOMER_CREDIT(...) ;

The syntax for saving a statement for later propagation is:

Note that it is also possible to merely save the statements for later propagation and not update the local database at all. In this case, the replica will get the updated information after it propagates the information to the master and then refreshes from updated data from the master.

The SAVEd statement is executed “as is” on the master; the statement does not carry with it any memory of which records on the replica were affected when it was executed on the replica. For example, suppose that you execute a series of statements like:

UPDATE employee_table SET salary = salary * 1.10
WHERE state = 'California';
SAVE UPDATE employee_table SET salary = salary * 1.10
WHERE state = 'California';

Suppose also that the master database contains 200 employees who work in California, while the replica contains only the 100 employees who worked at the local branch office in San Francisco, California. In that case, the UPDATE command executed on the replica would apply only to the 100 employees contained in the replica’s database, but the identical saved statement would apply to all 200 California employees listed in the master’s database. When you propagate a command to the master, be careful to use a WHERE clause that ensures that the command applies only to the appropriate records.