Re: performance problem - 10.000 databases

Hi,

Christopher Browne wrote, On 11/6/2003 4:40 PM:

> threshar(at)torgo(dot)978(dot)org (Jeff) writes:
>> On 06 Nov 2003 15:21:03 +0100
>> Marek Florianczyk <franki(at)tpi(dot)pl> wrote:
>>
>>> fsync = false
>>
>> HOLD THE BOAT THERE BATMAN!
>>
>> I would *STRONGLY* advise not running with fsync=false in production as
>> PG _CANNOT_ guaruntee data consistancy in the event of a hardware
>> failure. It would sure suck to have a power failure screw up your nice
>> db for the users!
>
> On one of our test servers, I set "fsync=false", and a test load's
> load time dropped from about 90 minutes to 3 minutes. (It was REALLY
> update heavy, with huge numbers of tiny transactions.)
>
> Which is, yes, quite spectacularly faster. But also quite
> spectacularly unsafe.
>
> I'm willing to live with the risk on a test box whose purpose is
> _testing_; it's certainly not a good thing to do in production.

There is something like: set fsync to off; or set fsync to on;
But it says: 'fsync' cannot be changed now. However could be very useful
to set this option from sql, not just from config.

Tom Lane probably knows why :)

C.