Re: Must the file be deleted after "copy binary into table from file"?

Stefan Manegold Stefan.Manegold at cwi.nl
Fri Jul 19 08:15:13 CEST 2013


Hi Meng,

for efficiently, i.e., to avoid a file copy, MonetDB's binary copy into simply moves(^) the user-provided and to be loaded files into its dbfarm.
Thus, if you need to preserve a copy of the files you provide, you need to do so yourself before executing a binary copy into.

Best,
Stefan

(^)

1) The actual behavior (move) is actually different than the copy that the documentation at http://www.monetdb.org/Documentation/Cookbooks/SQLrecipes/BinaryBulkLoad suggests. We need to fix the latter.

2) The actual behavior currently differs between data types; for numerical types, the user-provided files are moved as explained above; for stings, the files are read and processed, i.e., the used-provided file remains in place as-is. We need to consider unifying this behavior, e.g., by deleting also the user provided files for strings once they have been processed/loaded.

3) In case the copy into file, e.g., due to a failing sanity check after the file is moved, that data is factually lost, i.e., the files are gone, but no data is loaded into the database; we need to either document this clearly, or make the implementation behave like a transaction.



----- Original Message -----
> can i have the file reserved?
> 
> 
> 
> Thanks
> Meng
> _______________________________________________
> users-list mailing list
> users-list at monetdb.org
> http://mail.monetdb.org/mailman/listinfo/users-list
> 

-- 
| Stefan.Manegold at CWI.nl | DB Architectures   (DA) |
| www.CWI.nl/~manegold/  | Science Park 123 (L321) |
| +31 (0)20 592-4212     | 1098 XG Amsterdam  (NL) |




More information about the users-list mailing list