MySQL specific SQL doesn't work with PostgreSQL

I'm running drupal 5.4 with PostgreSQL 8.2.5 as database server.
I installed the xmlsitemap module from the latest cvs checkout and still encountered one issue while adding a new node of type page:

pg_query() [function.pg-query]: Query failed: ERROR: LIMIT #,# syntax is not supported HINT: Use separate LIMIT and OFFSET clauses. in D:\Websites\Stiegele\includes\database.pgsql.inc in Zeile 125.

query: INSERT INTO xmlsitemap_node (nid, pid, last_changed, priority_override) SELECT 151, ua.pid, 1197025923, NULL FROM node n LEFT JOIN url_alias ua ON ua.src = 'node/' || 151 LIMIT 0, 1 in D:\Websites\Stiegele\includes\database.pgsql.inc in Zeile 144.

The attached patch should resolve that issue.