ogr2ogr -f "PostgreSQL" PG:"host=* port=* dbname=* user=* password=*" RoFRS_v201701.gml -overwrite -progress --config PG_USE_COPY YES

Geometry: Polygon
Feature Count: 2130752
Extent: (134111.801000, 11510.471300) - (655988.124900, 657600.687500)
Layer SRS WKT:
(unknown)
OBJECTID: Integer (0.0)
PROB_4BAND: String (8.0)
SUITABILITY: String (25.0)
PUB_DATE: Integer (0.0)
RISK_FOR_INSURANCE_SOP: String (3.0)
SHAPE_Length: Real (0.0)
SHAPE_Area: Real (0.0)

ogrinfo PG:"host=* port=* dbname=* user=* password=*" -sql "CREATE EXTENSION postgis;"

ogr2ogr -f "PostgreSQL" PG:"host=* port=* dbname=* user=* password=*" RoFRS_v201701.gml -overwrite -progress -oo GML_ATTRIBUTES_TO_OGR_FIELDS=YES

- Ensures the geom column contains geometry of plain,
      ST_MultiPolygon and not the variant with additional dimensions

 -- Run the queries below to check the type of geometry currently stored
-- in the geom column
-- SELECT DISTINCT ST_GeometryType(geom) FROM schema.table; -- We want ST_MultiPolygon
-- SELECT DISTINCT ST_NDims(geom) FROM schema.table; -- We want 2

-- If the above reports > 2 dimensions, you can force it to 2d by:
-- Adding an additional column called geom_2d of the correct type and projection
ALTER TABLE schema.table
ADD COLUMN geom_2d geometry(MultiPolygon,27700);
-- UPDATing that new column by passing the original geometry through the ST_Force2D
-- PostGIS function
UPDATE schema.table SET geom_2d = ST_Force2D(geom);
-- Dropping the original geometry
ALTER TABLE schema.table DROP COLUMN geom;
-- Renaming the new column to geom
ALTER TABLE schema.table RENAME COLUMN geom_2d TO geom;
-- Clean up any duplicate vertices and other geometry problems
DELETE FROM schema.table WHERE ST_Area(geom) = 0.0;
UPDATE schema.table
SET geom = ST_Multi(ST_Buffer(geom, 0.0))
WHERE NOT ST_IsValid(geom);

-- And adding a spatial index to the new column
CREATE INDEX sidx_table_geom
  ON schema.table
 USING gist
(geom);