Re: nonblocking libpq large object access?

David Helgason <david@uti.is> writes:
> I was just wondering whether this was either:
>     - supported, or
>     - doable,

AFAIK no one has tried to make it work.  Offhand it seems you'd need
to modify the API for libpq's LO operations in order to handle this.

A workaround you could think about is invoking the LO functions via
ordinary SELECT commands, ignoring libpq's LO API altogether.  This
would have been rather painful in pre-7.4 releases since you'd have
to be willing to deal with quoting and dequoting "bytea" values, but
as of 7.4 you could use PQsendQueryParams() and specify binary format
for the bytea inputs and results.

            regards, tom lane