Operating-system files
The DataBlade® API supports the functions for conversion between operating-system files and smart large objects.
| DataBlade API function | Description |
|---|---|
| mi_lo_from_file(), mi_lo_from_file_by_lofd() | Copies data in an operating-system file to a smart large object |
| mi_lo_to_file(), mi_lo_filename() | Copies data in a smart large object to an operating-system file |
The file functions have a set of file-mode constants that
are distinct from the open modes of smart large objects, as the following
table shows.
| File mode for operating-system files | Purpose |
|---|---|
| MI_O_EXCL | Fail if the file already exists |
| MI_O_APPEND | Append to the end of file |
| MI_O_TRUNC | Truncate to zero if file exists |
| MI_O_RDWR | Read/write mode (default) |
| MI_O_RDONLY | Read-only mode (copying from operating-system files only) |
| MI_O_WRONLY | Write-only mode (copying to operating-system files only) |
| MI_O_TEXT | Text mode (default off) |
| MI_O_CLIENT_FILE | Indication that file is on client computer (default) |
| MI_O_SERVER_FILE | Indication that file is on server computer |
You can include an environment variable in the file name path for the mi_lo_to_file(), mi_lo_from_file(), and mi_lo_from_file_by_lofd() functions. This environment variable must be set in the server environment; that is, it must be set before the database server starts.