Neither. The right answer is to use the GIS Spatial Type for a point. All of those database have their own implementation.

[PostgreSQL's PostGIS](https://postgis.net/docs/using_postgis_dbmanagement.html#PostGIS_Geography) is easily the most full featured GIS implementation,

    CREATE TABLE foo(
      gid  int GENERATED BY DEFAULT AS IDENTITY,
      geog geography(POINT)
    );

See also,

* [MySQL Spatial Data Types](https://dev.mysql.com/doc/refman/8.0/en/spatial-types.html) (which suck btw),
* [SQLite Spatial Extension SpatiaLite](https://www.gaia-gis.it/fossil/libspatialite/index)