Re: [PERFORM] Tunning postgresql on linux (fedora core 3)

Din Adrian wrote:
> sorry about cc ...
> this is the site:
> http://www.varlena.com/varlena/GeneralBits/Tidbits/annotated_conf_e.html
> but I gues is not right ... hmm

It's not that it's incorrect, just that you should always use the 
manuals as a starting point.

> On Thu, 03 Feb 2005 14:52:04 +0000, Richard Huxton <dev@archonet.com>  
> wrote:
> 
>> I'll repeat myself:
>>
>>
>>
>>
>> Please CC the mailing list as well as replying to me, so that others
>> can  help too.
>>
>>
>>
>>
>> Din Adrian wrote:
>>
>>>  On Thu, 03 Feb 2005 13:56:50 +0000, Richard Huxton 
>>> <dev@archonet.com>   wrote:
>>>
>>>> Please CC the mailing list as well as replying to me, so that 
>>>> others  can  help too.
>>>>
>>>>
>>>>>  b) in docs say that after 7.2 seting this to false does'n turn 
>>>>> off   the  wall ...!? wich option does?
>>>>
>>>>
>>>>
>>>> The docs don't say that, as far as I can see. It doesn't make sense  
>>>> to  turn off the WAL.
>>>
>>>   hmm this is the doc about ...
>>>  ' NOTE: Since 7.2, turning fsync off does NOT stop WAL. It does 
>>> stop   checkpointing, however. This is a change in the notes that 
>>> follow Turn  WAL  off (fsync=false) only for a read-only database or 
>>> one where the  database  can be regenerated from external software. 
>>> While RAID plus  UPSes can do a  lot to protect your data, turning 
>>> off fsync means that  you will be  restoring from backup in the event 
>>> of hardware or power  failure.'
>>
>>
>> I don't know what this is, and you don't give a URL, but it DOES NOT  
>> appear to be in the manuals.
>>
>> You should probably read the sections of the manuals regarding 
>> "run-time  configuration" and "write ahead logs". The manuals are 
>> quite extensive,  are available online at http://www.postgresql.org/ 
>> and also in most  distributions.
>>
>> This is probably a good place to start.
>> http://www.postgresql.org/docs/8.0/interactive/runtime-config.html#RUNTIME-CONFIG-WAL 
>>
>>
>>> If you turn it off you should have more speed ... !!!???
>>
>>
>> Basically, as I said in my last email - fsync=true makes sure  
>> transaction details are safely stored on disk. If you turn this off, 
>> the  database doesn't have to wait for the data to physically be 
>> written to  the disk. But, if power fails then data might be in OS or 
>> disk cache and  so lost when you restart the machine.
>>
>> Please CC the mailing list if you reply to this message.
>> -- 
>>    Richard Huxton
>>    Archonet Ltd
>>
> 
> 
> 


--   Richard Huxton  Archonet Ltd