Response time measures the performance of an individual
transaction or query. Response time is typically treated as the elapsed
time from the moment that a user enters a command or activates a function
until the time that the application indicates that the command or
function has completed.
The response time for a typical Informix® application
includes the following sequence of actions. Each action requires a
certain amount of time. The response time does not include the time
that it takes for the user to think of and enter a query or request:
The application forwards a query to the database server.
The database server performs query optimization and retrieves
any user-defined routines (UDRs). UDRs include both SPL routines and
external routines.
The database server retrieves, adds, or updates the appropriate
records and performs disk I/O operations directly related to the query.
The database server performs any background I/O operations, such
as logging and page cleaning, that occur during the period in which
the query or transaction is still pending.
The database server returns a result to the application.
The application displays the information or issues a confirmation
and then issues a new prompt to the user.
Components of the response time for
a single transaction contains a
diagram that shows how the actions just described in steps 1 through
6 contribute to the overall response time. Figure 1: Components of the response time for
a single transaction