Editing metadata in PostGIS database?

You can create a table in PostgreSQL to store your metadata. For example call it public.metadata with the columns you need for your metadata schema.

This would be the best way to store metadata in PostgreSQL.

PostgreSQL lets you store information about tables, columns, or numerous other objects using comments. If you choose, you can use the comment field to store a JSON or XML representation of attributes such as author, time of creation, measurement units, etc.

To set the comment on a table, use:

COMMENT ON TABLE my_table IS '{ "author" : "dbaston" }';

Comments can be viewed with the obj_description function:

SELECT obj_description('public.my_table'::regclass);