Re: Postgres Performance Tuning

Thanks Scott :

My iostat package is not installed but have a look on below output:

[root(at)s8-mysd-2 8.4SS]# vmstat 10
procs -----------memory---------- ---swap-- -----io---- --system--
-----cpu------
r b swpd free buff cache si so bi bo in cs us sy
id wa st
1 0 147664 93920 72332 15580748 0 1 113 170 47 177 6
1 92 1 0
0 0 147664 94020 72348 15580748 0 0 0 4 993 565 0
0 100 0 0
0 0 147664 93896 72364 15580748 0 0 0 5 993 571 0
0 100 0 0
0 0 147664 93524 72416 15580860 0 0 0 160 1015 591 0
0 100 0 0
0 0 147664 93524 72448 15580860 0 0 0 8 1019 553 0
0 100 0 0
0 0 147664 93648 72448 15580860 0 0 0 0 1019 555 0
0 100 0 0
0 0 147664 93648 72448 15580860 0 0 0 3 1023 560 0
0 100 0 0

[root(at)s8-mysd-2 8.4SS]# iostat
-bash: iostat: command not found
[root(at)s8-mysd-2 8.4SS]#

Best regards,
Adarsh

Scott Marlowe wrote:
> On Mon, Apr 4, 2011 at 5:34 AM, Adarsh Sharma <adarsh(dot)sharma(at)orkash(dot)com> wrote:
>
>> Mem: 16299476k total, 16198784k used, 100692k free, 73776k buffers
>> Swap: 16787884k total, 148176k used, 16639708k free, 15585396k cached
>>
>> PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+
>> COMMAND
>> 3401 postgres 20 0 4288m 3.3g 3.3g S 0 21.1 0:24.73
>> postgres
>> 3397 postgres 20 0 4286m 119m 119m S 0 0.8 0:00.36
>> postgres
>> PLease help me to understand how much memory does 1 Connection Uses and how
>> to use Server parameters accordingly.
>>
>
> OK, first, see the 15585396k cached? That's how much memory your OS
> is using to cache file systems etc. Basically that's memory not being
> used by anything else right now, so the OS borrows it and uses it for
> caching.
>
> Next, VIRT is how much memory your process would need to load every
> lib it might need but may not be using now, plus all the shared memory
> it might need, plus it's own space etc. It's not memory in use, it's
> memory that might under the worst circumstances, be used by that one
> process. RES is the amount of memory the process IS actually
> touching, including shared memory that other processes may be sharing.
> Finally, SHR is the amount of shared memory the process is touching.
> so, taking your biggest process, it is linked to enough libraries and
> shared memory and it's own private memory to add up to 4288Meg. It is
> currently actually touching 3.3G. Of that 3.3G it is touching 3.3G is
> shared with other processes. So, the difference between RES and SHR
> is 0, so the delta, or extra memory it's using besides shared memory
> is ZERO (or very close to it, probably dozens or fewer of megabytes).
>
> So, you're NOT running out of memory. Remember when I mentioned
> iostat, vmstat, etc up above? Have you run any of those?
>