ST_Estimated_Extent — Return the 'estimated' extent of the given spatial table. The estimated is taken from the geometry column's statistics. The current schema will be used if not specified.
box2d ST_Estimated_Extent(
text schema_name, text table_name, text geocolumn_name)
;
box2d ST_Estimated_Extent(
text table_name, text geocolumn_name)
;
Return the 'estimated' extent of the given spatial table. The estimated is taken from the geometry column's statistics. The current schema will be used if not specified.
For PostgreSQL>=8.0.0 statistics are gathered by VACUUM ANALYZE and resulting extent will be about 95% of the real one.
For PostgreSQL<8.0.0 statistics are gathered by update_geometry_stats() and resulting extent will be exact.
This method supports Circular Strings and curves