| 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.)
Read the upstream documentation. For corrections, first check the current version.