}
+/*
+ * old_8_3_check_ltree_usage()
+ * 8.3 -> 8.4
+ * The internal ltree structure was changed in 8.4 so upgrading is impossible.
+ */
+void
+old_8_3_check_ltree_usage(migratorContext *ctx, Cluster whichCluster)
+{
+ ClusterInfo *active_cluster = (whichCluster == CLUSTER_OLD) ?
+ &ctx->old : &ctx->new;
+ int dbnum;
+ FILE *script = NULL;
+ bool found = false;
+ char output_path[MAXPGPATH];
+
+ prep_status(ctx, "Checking for /contrib/ltree");
+
+ snprintf(output_path, sizeof(output_path), "%s/contrib_ltree.txt",
+ ctx->cwd);
+
+ for (dbnum = 0; dbnum < active_cluster->dbarr.ndbs; dbnum++)
+ {
+ PGresult *res;
+ bool db_used = false;
+ int ntups;
+ int rowno;
+ int i_nspname,
+ i_proname;
+ DbInfo *active_db = &active_cluster->dbarr.dbs[dbnum];
+ PGconn *conn = connectToServer(ctx, active_db->db_name, whichCluster);
+
+ /* Find any functions coming from contrib/ltree */
+ res = executeQueryOrDie(ctx, conn,
+ "SELECT n.nspname, p.proname "
+ "FROM pg_catalog.pg_proc p, "
+ " pg_catalog.pg_namespace n "
+ "WHERE p.pronamespace = n.oid AND "
+ " p.probin = '$libdir/ltree'");
+
+ ntups = PQntuples(res);
+ i_nspname = PQfnumber(res, "nspname");
+ i_proname = PQfnumber(res, "proname");
+ for (rowno = 0; rowno < ntups; rowno++)
+ {
+ found = true;
+ if (script == NULL && (script = fopen(output_path, "w")) == NULL)
+ pg_log(ctx, PG_FATAL, "Could not create necessary file: %s\n", output_path);
+ if (!db_used)
+ {
+ fprintf(script, "Database: %s\n", active_db->db_name);
+ db_used = true;
+ }
+ fprintf(script, " %s.%s\n",
+ PQgetvalue(res, rowno, i_nspname),
+ PQgetvalue(res, rowno, i_proname));
+ }
+
+ PQclear(res);
+
+ PQfinish(conn);
+ }
+
+ if (found)
+ {
+ fclose(script);
+ pg_log(ctx, PG_REPORT, "fatal\n");
+ pg_log(ctx, PG_FATAL,
+ "| Your installation contains the \"ltree\" data type. This data type\n"
+ "| changed its internal storage format between your old and new clusters so this\n"
+ "| cluster cannot currently be upgraded. You can manually upgrade databases\n"
+ "| that use \"contrib/ltree\" facilities and remove \"contrib/ltree\" from the old\n"
+ "| cluster and restart the upgrade. A list of the problem functions is in the\n"
+ "| file:\n"
+ "| \t%s\n\n", output_path);
+ }
+ else
+ check_ok(ctx);
+}
+
+
/*
* old_8_3_rebuild_tsvector_tables()
* 8.3 -> 8.4