These topics describe the purpose functions that the access-method
developer provides.
Purpose-function flow
The diagrams in this section show, for each SQL statement,
which purpose functions the database server executes. Use the diagrams
to determine which purpose functions to implement in the access method.
Purpose-function syntax
The database server expects a particular prototype for
each purpose function. As the access-method developer, you program
the actions of a purpose function but must use the parameters and
return values that the Virtual-Index Interface (VII) prototypes specify.