Re: Must the file be deleted after "copy binary into table from file"？
Stefan.Manegold at cwi.nl
Fri Jul 19 08:15:13 CEST 2013
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.
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?
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> users-list at monetdb.org
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