SELECT *
FROM   gst.proscatalog_
WHERE  NOT EXISTS(SELECT *
                  FROM   information_schema.tables
                  WHERE  table_schema = Substring(geotablename, 0,
                                        Position('.' IN geotablename))
                         AND table_name = Substring(geotablename,
                                          Position('.' IN geotablename) +
                                          1));

SELECT *
FROM   gst.proscatalog_
WHERE prostablename <> ''
  AND NOT EXISTS(SELECT *
                  FROM   information_schema.tables
                  WHERE  table_schema = Substring(prostablename, 0,
                                        Position('.' IN geotablename))
                         AND table_name = Substring(prostablename,
                                          Position('.' IN geotablename) +
                                          1));