Re: PostgreSQL on 64 bit Linux

Naz,

On 8/20/06 12:59 PM, "Naz Gassiep" <naz(at)mira(dot)net> wrote:

> I have a PostgreSQL installation on a Debian box that had the 64bit SMP
> kernel installed before PostgreSQL was compiled and installed on it.
> Does PostgreSQL take any advantage of the 64 bit environment or have we
> not done anything to move into the 64 bit world yet?

Very likely the default gcc compiles for 64-bit, if not you need to specify
"-m64". As another respondent said - do a "file `which initdb`" to find out
whether you have compiled for 64-bit or not.

WRT 64-bit and Postgres, it depends on the CPU as to whether you see a
simple performance benefit. On the Opteron you will see a benefit when
doing CPU bound work. When doing the CPU portion, the additional registers
of the Opteron running in 64-bit mode are used by the compiler to produce a
20-30% boost in performance. On the Xeon in 64-bit mode, the same regions
of execution will slow down by about 5%.

Postgres benefits automatically from the larger memory addressing of the
64-bit kernel by using the larger I/O cache of Linux.

- Luke