| PostgreSQL 7.4.30 Documentation | ||||
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There are two built-in server-side functions, lo_import
and lo_export, for large object access, which are available
for use in SQL commands. Here
is an example of their use:
CREATE TABLE image (
name text,
raster oid
);
INSERT INTO image (name, raster)
VALUES ('beautiful image', lo_import('/etc/motd'));
SELECT lo_export(image.raster, '/tmp/motd') FROM image
WHERE name = 'beautiful image';
These functions read and write files in the server's file system, using the permissions of the database's owning user. Therefore, their use is restricted to superusers. (In contrast, the client-side import and export functions read and write files in the client's file system, using the permissions of the client program. Their use is not restricted.)