Choose DataBlade API functions

The type of storage space determines whether you use mi_file_*() functions or mi_lo_*() functions to open, close, read from, and write to data.

To have the access method store data in an sbspace, use the smart-large-object interface of the DataBlade API. The names of most functions of the smart-large-object interface begin with the mi_lo_ prefix. For example, you open a smart large object in an sbspace with mi_lo_open() or one of the smart-large-object creation functions: mi_lo_copy(), mi_lo_create(), mi_lo_expand(), or mi_lo_from_file().

If the access method stores data on devices that the operating system manages, use the DataBlade API file-access functions. Most file-access functions begin with the mi_file_ prefix. For example, the am_open purpose function might open a disk file with mi_file_open().

Restriction: Do not use operating-system commands to access data in an extspace.

For more information about smart-large-object functions and file-access functions, see the HCL Informix® DataBlade API Programmer's Guide.

If another database manager reads and writes the data, pass input/output requests to the external database manager.