Does anyone know whether cygwin has a setting comparable to SHMMAX, and if so what is its default value? How about the upcoming native Windows port --- any issues there?
From a pure win32 point of view, a good approach would be to use the VirtualAlloc() memory allocation functions and set up a paged memory allocation system. From a very top down point of view, this is the method of choice if portability is not an issue. An abstraction to use this technique within pg context is probably complex and requires writing lots of win32 api code, which is obviously not desirable. Another way of looking at it is memory mapped files. This probably most closely resembles unix shared memory and is the de facto standard way for interprocess memory block sharing. Sadly, performance will suffer because you have to rely on the virtual memory system (think: writing to files) to do a lot of stupid stuff you don't necessarily want or need. The OS has to guarantee that the memory can be swapped out to file at any time and therefore mirrors the pagefile to the allocated memory blocks. With the C++/C memory malloc/free api, you are supposed to be able to get some of the benefits of virtual alloc (in particular, setting a process memory allocation limit), but personal experience did not bear this out. However, this api sits directly over the virtual allocation system and is the most portable. The application has to guard against fragmentation and things like that in this case. In win32, server thrashing is public enemy #1 for database servers, mostly due to the virtual allocation system (which is quite fast when used right, btw). Merlin ---------------------------(end of broadcast)--------------------------- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
