Stephen, You're a legend! That is exactly the answer I needed to hear from someone who actually knows the score. I am now powering on with Plan B: Postgres64 on Linux64.
After relentless searching I have become fairly convinced that a stable release of 64-bit postgres for Windows doesn't exist yet. (I welcome anyone to show me otherwise). Since I am committed to postgres (already written the code, it works just not quickly), I will have to change my OS. However, if these performance limitations on Windows were apparent to me from the start, I probably would have chosen MS SQL Server over Postgres (less pain to get the gain). Perhaps this is an argument in favour of 64-bit Windows port to be added to this list: http://wiki.postgresql.org/wiki/64bit_Windows_port Thanks again for all your help. Tom On 2 June 2010 15:27, Stephen Frost <sfr...@snowman.net> wrote: > Tom, > > * Tom Wilcox (hungry...@googlemail.com) wrote: > > The impression I was getting from Magnus Hagander's blog was that a > 32-bit > > version of Postgres could make use of >4Gb RAM when running on 64-bit > > Windows due to the way PG passes on the responsibility for caching onto > the > > OS.. Is this definitely not the case then? > > Eh, sure, the data will be cache'd in the Windows OS, so more data will > be in memory, but you're never going to be able to use more than 4G for > any actual *processing*, like sorting, doing hash joins, having data in > shared buffers (to avoid having to go back to the OS and doing a system > call to get the data from the OS's cache..). > > Not only that, but the shared_buffers are in *every* backend, so while > you'll only use 512MB for shared_buffers total, each backend will only > have 3.5G (or so) of memory to do 'other stuff'. > > On a box with 16GB that's doing alot of relatively small activities > (OLTP type stuff), PG will work "alright". On a box with 96G with > terrabytes of data where you want to do data warehousing kind of work, > running a 32bit version of PG is going to suck. > > Thanks, > > Stephen > > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.9 (GNU/Linux) > > iEYEARECAAYFAkwGalUACgkQrzgMPqB3kigWugCfY411is3uy3grP6lSH3P+neaf > evYAn2vY8/V3GntpQA9Q434U79+GThSW > =ar57 > -----END PGP SIGNATURE----- > >
