| dest | source file identifier |
| source | source file identifier |
| key | description of index to cluster on or NULL |
SUCCESS, or a negative value on error, in which case the error code is found in iserrno.
iscopy will copy all records from source into destination, in the order specified by key.
if key is NULL, the current order will be used.
be warned that this call may take some time to run if the file in question is large.