Using FastPath
The access method can use a DataBlade API facility called FastPath to execute registered UDRs that are not in the same shared-object module as the access-method functions.
To
use the FastPath facility, the access method completes the following
general steps:
- Obtains a routine identifier for the desired UDR.
- Passes the routine identifier to the DataBlade API mi_func_desc_by_typeid() function, which returns the function descriptor.
- Passes the function descriptor to the DataBlade API mi_routine_exec() function, which executes the function in a virtual processor.
For complete information about FastPath functions and
the function descriptor (MI_FUNC_DESC), see the HCL
Informix®
DataBlade API Programmer's Guide.
Important: A database server exception results if a parallelizable
function attempts to execute a routine that is not parallelizable.
Use mi_func_desc_by_typeid() and mi_routine_exec() from
a parallelizable access method only if you can guarantee that these
functions look up or execute a parallelizable routine.