Variable record fetching

Hi,

I am working on converting Informix database to Postgre. I have one
question for fetching records using PostgreSQL. The record I am fetching
is a variable size text string. Before fetching the record, a
preallocated static buffer size will have to be declared beforehand in
the declaration section. Since the record sizes vary a lot, instead of
using the static buffer, is there a dynamic way to fetch these records?
Informix (Oracle has the similar feature) has the locator variable and
the server will allocate the buffer if you initiate the locator to
accommodate the record. The application then checks the locator size
(record.loc_bufsize) to dynamically allocate a buffer to fetch it out
and free the locator buffer. Does Postgre have any way to pre-tell the
size of returning record? Thanks.

Shujun Huang