Actually server and client are installed on the same machine.
The file (real file) permissions are as follows:
-rwxrwxrwx+ 1 kaj kaj 2 Oct 27 22:36 fd/fdo.txt
The directory permissions are as follows:
drwxrwxrwx+ 4 kaj kaj 4096 Oct 27 22:36 fd
The SQL command which tries to write to the file is this:
copy (select key from xcg where add=false) to '/home/kaj/fd/fdo.txt';
Pozdrawiam
Krzysztof Jasieński
On 10/29/25 5:12 PM, Roland Müller wrote:
Hello,
COPY TO stores the output into a file on the server rather than in your local where client is running.
Spaces in the file name are actually no issue:
$ psql -h 172.17.0.2 -U postgres -c "COPY (SELECT * FROM pg_class) TO '/var/tmp/pg_class. OUT x'"
Password for user postgres:
COPY 420
... but the output file is on the server - in this example inside a docker container
postgres@7680e256387f:~$ ls -ltr /var/tmp
total 208
...
-rw-r--r-- 1 postgres postgres 49291 Oct 29 16:08 'pg_class. OUT x'
Copying to client side can be done with \copy (<query or table>) to '<output file>';
BR/Pozdrawiam,
Roland
On 10/29/25 01:03, Rob Sargent wrote:
I try to use COPY TO command to copy results of a SELECT but I get this message:
ERROR: could not open file "a file" for writing: Permission denied
Is there really a space in the actual file name. That might get tricky. You’re suggesting the file already exists: is that true? Directory permissions?
User, group and other are granted full permission to this file. What should I do more to get this working?
--
Pozdrawiam
Krzysztof Jasieński
