PostgreSQL equivalents to dbms_metadata.get_ddl & dbms_metadata.get_dependent_ddl

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.