[GENERAL] psql lo_export documentation

From: Jorgen Austvik - Sun Norway <Jorgen.Austvik(at)Sun.COM>
Date: Fri Nov 30 2007 - 05:31:01 EST

Hi,

The 8.3 psql documentation says this about lo_export:

------8<------------8<------------8<------------8<------------8<------------8<------

       

         <term><literal>\lo_export <replaceable 

class="parameter">loid</replaceable> <replaceable class="parameter">filename</replaceable></literal></term>

<listitem>
<para>

         Reads the large object with OID loid from the database and
         writes it to filename. Note that this is
         subtly different from the server function

         <function>lo_export</function>, which acts with the permissions

         of the user that the database server runs as and on the server's
         file system.

         </para>
         <tip>
         <para>

         Use \lo_list to find out the large object's

         <acronym>OID</acronym>.
         </para>
         </tip>
         </listitem>

       

------8<------------8<------------8<------------8<------------8<------------8<------

Below is an error message I get when I try to use lo_export from client:

------8<------------8<------------8<------------8<------------8<------------8<------ other_database=> SELECT lo_export(16391, '/tmp/file') FROM lotest_stash_values;
ERROR: must be superuser to use server-side lo_export() HINT: Anyone can use the client-side lo_export() provided by libpq. ------8<------------8<------------8<------------8<------------8<------------8<------

With experiments I find that lo_export on 8.3 stores the files on the database server file system. I also think it would be good if the documentation said that you need to be database superuser to use this

Something along the lines of this?

   Note that this acts with the permissions of the user that the    database server runs as and on the server's file system. Therefore you    have to be a database superuser to be allowed to use this function.

On 8.2 I get this on client side import, this is fixed in 8.3. ------8<------------8<------------8<------------8<------------8<------------8<------ other_database=> INSERT INTO lotest_stash_values (loid) SELECT lo_import('/export/home/ja155679/random_data.dat'); ERROR: must be superuser to use server-side lo_import() HINT: Anyone can use the client-side lo_import() provided by libpq. ------8<------------8<------------8<------------8<------------8<------------8<------

So, on 8.2 it looks for me like you had to be database superuser to be able to run lo_import, and that files would import from the server, and that that now is changed in 8.3 so that the files are imported from the client.

Do we really want lo_import and lo_export to work on different file systems?

-J

-- 

Jørgen Austvik, Software Engineering - QA
Sun Microsystems Database Technology Group

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Received on Fri Nov 30 05:32:12 2007