Export postgres table to csv error - database

Question

I am trying to export all my tables of postrgres into individual csv files for that I am using the following function
CREATE OR REPLACE FUNCTION db_to_csv(path text)
RETURNS void AS
$BODY$
declare
tables RECORD;
statement TEXT;
begin
FOR tables IN
SELECT (table_schema || '.' || table_name) AS schema_table
FROM information_schema.tables t INNER JOIN information_schema.schemata s
ON s.schema_name = t.table_schema
WHERE t.table_schema NOT IN ('pg_catalog', 'information_schema', 'configuration')
ORDER BY schema_table
LOOP
statement := 'COPY ' || tables.schema_table || ' TO ''' || path || '/' || tables.schema_table || '.csv' ||''' DELIMITER '';'' CSV HEADER';
EXECUTE statement;
END LOOP;
return;
end;
$BODY$
LANGUAGE plpgsql VOLATILE
COST 100;
ALTER FUNCTION db_to_csv(text)
OWNER TO postgres;
but when I am calling this function I am getting could not open file "/home/user/Documents/public.tablename.csv" for writing: Permission denied
I have tried copying individual table using
COPY activities TO '/home/user/Documents/foldername/conversions/tablename.csv' DELIMITER ',' CSV HEADER;
It gives me the following error
ERROR: could not open file "/home/user/Documents/foldername/conversions/tablename.csv" for writing: Permission denied
********** Error **********
ERROR: could not open file "/home/user/Documents/foldername/conversions/tablename.csv" for writing: Permission denied
SQL state: 42501
Any suggestions how to fix this.

Answer 1

Make a folder on which every user has access. Then run the COPY command on a file there. COPY works only on directories where postgres user has access
sudo mkdir /media/export
sudo chmod 777 /media/export
COPY activities TO '/media/export/activities.csv' DELIMITER ',' CSV HEADER;

Answer 2

I was facing the same issue and I followed the second answer
Make a folder on which every user has access. Then run the COPY command on a file there. COPY works only on directories where postgres user has access
This didn't work for me.
So, I performed copy to /tmp/somename.csv and then copied the file to my actual required location for usage.
\copy query TO '/tmp/somename.csv' with csv;

Answer 3

Not working after given permission.
Now I tried to export the same location where greenplum data available i.e greenplum/data, now permission denied problem get resolved.
COPY Table_Name TO '/home/greenplum/data/table_data_export.csv';