Thanks, that's answering my question. In Objective-C as well as many other 
languages there is the feature to turn on Garbage Collection. It's a separate 
thread that scans memory for strong pointers, their source and origin and 
"vacuums" memory so to not have any leaks. Anything unreferenced and no longer 
needed is cleaned up automatically. There are some border cases where GC can 
fail, but for most it works.

There are three values for the compiler: off, supported and required. One 
cannot mix subprojects unlike in e.g. ARC (Automated Reference Counting). 
Either it's on or off. Supported means that it covers both sides, "manual" 
memory management and automated management.

As GC is an evolutionary stage across languages, objects formerly deallocated 
or freed or released (or whatever other term is used across different 
languages) through a unique call or method name where one would normally also 
host any steps to release associated resources not necessarily memory related 
(closing sockets, file handles etc.), such call is replaced with the language 
specific call that the garbage collector calls to still provide for closing 
these resources while still being able to handle memory management in an 
automated fashion. All directly memory related calls become no-ops to provide 
for backward compatibility. In the end one can compile with GC on, or GC off 
and the compiler refers to the calls it needs to deal with the two aspects 
accordingly, either resource-only management or resource-and-memory management.

In general there are libs that provide garbage collection for C as well, like 
here:
<http://www.hpl.hp.com/personal/Hans_Boehm/gc/>

For example, it'd help avoid leaks like those caused by a result not being 
PQclear'ed.

Alex


Am 03.05.2012 um 09:16 schrieb Peter Bex:

> On Thu, May 03, 2012 at 09:08:53AM +0200, Alexander Reichstadt wrote:
>> 
>> Hi,
>> 
>> since I got no answer so far I searched through the docu again. I searched 
>> for GC as well as Garbage, and all garbage refers to is with regard to 
>> vacuuming a database. But my question refers to wether or not memory 
>> management is with garbage collection supported or not. When I try to link 
>> against pqlib, it seems I need to have garbage collection enabled in order 
>> for it to link. But the documentation mentions it nowhere.
> 
> What kind of garbage collection do you need to have enabled in order to link?
> 
> C is based on manual memory-management, and you can't generally have
> garbage-collection in it.  Hence, libpq is *not* garbage-collected and
> your statement that it needs "garbage collection enabled" doesn't make
> much sense to me.
> 
> Are you talking about libpq bindings to some other language, perhaps?
> 
>> Please, can someone confirm this or is this the wrong list?
> 
> This is the right list.
> 
> Cheers,
> Peter
> -- 
> http://sjamaan.ath.cx
> --
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> is especially attractive, not only because it can be economically
> and scientifically rewarding, but also because it can be an aesthetic
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>                                                       -- Donald Knuth
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