problem in PostGIS Name of the system used for Points and how to get distance between to point?

Question

I have started to work on a project in PostGIS.

I have a table with a geometry points in which points saved like this : "010100000089F511C671C01E4162327E2A83545341"

and I have translated this point in postgis using : ST_AsText(geometry g1); and the result was : "POINT(494852.884569681 5059777.30183276)"

I dont know the name of this systems.....I want to get the distance between to point ??

Would you please help me what is the name of this systems and how can I get the distance between points ?

Answer 1

You can use the function ST_SRID to get the spatial reference identifier.

To get the distance between points you can use the function ST_DISTANCE.