Installing 64 bit postgresql

[VastOne]

Binary package hint: postgresql-8.3

sudo aptitude install postgresql goes through install but reports failure with message that it cannot install with this version of Ubuntu (Intrepid)

ProblemType: Package
Architecture: amd64
DistroRelease: Ubuntu 8.10
ErrorMessage: subprocess post-installation script returned error exit status 1
NonfreeKernelModules: nvidia
Package: postgresql-8.3 8.3.5-0ubuntu8.10
SourcePackage: postgresql-8.3
Title: package postgresql-8.3 8.3.5-0ubuntu8.10 failed to install/upgrade: subprocess post-installation script returned error exit status 1
Uname: Linux 2.6.27-9-generic x86_64

[cad106uk (cad106uk-gmail)]

sudo /etc/init.d/postgresql-8.3 restart
 * Restarting PostgreSQL 8.3 database server * The PostgreSQL server failed to start. Please check the log output:
2009-02-11 21:18:50 GMT LOG: could not load root certificate file "root.crt": no SSL error reported
2009-02-11 21:18:50 GMT DETAIL: Will not verify client certificates.
2009-02-11 21:18:50 GMT FATAL: could not create shared memory segment: Invalid argument
2009-02-11 21:18:50 GMT DETAIL: Failed system call was shmget(key=5432001, size=39288832, 03600).
2009-02-11 21:18:50 GMT HINT: This error usually means that PostgreSQL's request for a shared memory segment exceeded your kernel's SHMMAX parameter. You can either reduce the request size or reconfigure the kernel with larger SHMMAX. To reduce the request size (currently 39288832 bytes), reduce PostgreSQL's shared_buffers parameter (currently 4096) and/or its max_connections parameter (currently 103).
 If the request size is already small, it's possible that it is less than your kernel's SHMMIN parameter, in which case raising the request size or reconfiguring SHMMIN is called for.
 The PostgreSQL documentation contains more information about shared memory configuration.

uname -a
Linux willow 2.6.27-11-generic #1 SMP Thu Jan 29 19:28:32 UTC 2009 x86_64 GNU/Linux