Question

Say you create a directory like:

CREATE OR REPLACE DIRECTORY 
EXT_DATA_FILES AS 
'/data/ext_data_files';
GRANT READ, WRITE ON DIRECTORY SYS.EXT_DATA_FILES TO MYAPPUSER;

I want to know if Oracle is capable of reading and writing files into that path. How could I test it?

That would help me a lot when creating external tables to avoid obscure error messages not really related to permissions error.

Answer 1

You can use the UTL_FILE package. For example, this will verify that you can create a new file named some_new_file_name.txt in the directory and write data to it

DECLARE
  l_file utl_file.file_type;
BEGIN
  l_file := utl_file.fopen( 'EXT_DATA_FILES', 'some_new_file_name.txt', 'W' );
  utl_file.put_line( l_file, 'Here is some text' );
  utl_file.fclose( l_file );
END;

This will verify that a file named existing_file_name.txt exists and is readable

DECLARE
  l_exists     boolean;
  l_size       integer;
  l_block_size integer;
BEGIN
  utl_file.fgetattr( 'EXT_DATA_FILES', 
                     'existing_file_name.txt', 
                     l_exists, 
                     l_size, 
                     l_block_size );
   if( l_exists )
   then
     dbms_output.put_line( 'The file exists and has a size of ' || l_size );
   else
     dbms_output.put_line( 'The file does not exist or is not visible to Oracle' );
   end if;
END;