Description
string 
pg_last_oid ( resource result )
   pg_last_oid() is used to retrieve the
   OID assigned to an inserted row.
  
   OID field became an optional field from PostgreSQL 7.2 and will
   not be present by default in PostgreSQL 8.1. When the
   OID field is not present in a table, the programmer must use 
   pg_result_status() to check for successful
   insertion.
  
   To get the value of a SERIAL field in an inserted
   row, it is necessary to use the PostgreSQL CURRVAL
   function, naming the sequence whose last value is required.  If the
   name of the sequence is unknown, the pg_get_serial_sequence
   PostgreSQL 8.0 function is necessary.
  
   PostgreSQL 8.1 has a function LASTVAL that returns
   the value of the most recently used sequence in the session.  This avoids
   the need for naming the sequence, table or column altogether.
  
Note: 
    This function used to be called pg_getlastoid().