PostgreSQL equivalents to dbms_metadata.get_ddl & dbms_metadata.get_dependent_ddl

Hello all,
I am trying to find a simple way to get access the DDL information for
PostgreSQL tables, constraints, and indices via SQL.

In Oracle there are the dbms_metadata.get_ddl()
and dbms_metadata.get_dependent_ddl() functions that you can call on dual
to get this information.

EX:
-- table DDL:
select dbms_metadata.get_ddl('TABLE', 'MY_TABLE','MY_SCHEMA') as
"table_ddl" from dual;

-- indices DDL
select dbms_metadata.get_dependent_ddl('INDEX','MY_TABLE','MY_SCHEMA') as
"table_indicies" from dual;

-- constraints DDL
select dbms_metadata.get_dependent_ddl('CONSTRAINT','MY_TABLE','MY_SCHEMA')
as "constraints_ddl" from dual;

Is there an equivalent function to do the same in PostgreSQL?

I know there are ways via pg_dump and psql, but what I need is a way to do
so via SQL.

Thanks,
rik.