Re: Nasty VACUUM/bgwriter/segmentation bug

Heikki Linnakangas wrote:
> Florian G. Pflug wrote:
>> Joshua D. Drake wrote:
>>> On Sun, 2006-11-19 at 11:28 -0800, Josh Berkus wrote:
>>>> Tom,
>>>>> Let's go with the easy fix. With regular 1GB segment size, having a 
>>>>> few
>>>>> empty files in the data directory isn't going to hurt anyone.
>>>> No, but it will confuse DBAs ("What the heck are all these 0B 
>>>> files?").  Maybe we should add code to VACUUM to look for these 
>>>> empty file segments and unlink them if they haven't been touched in 
>>>> a while (say, a day?).
>>>
>>> I don't buy this argument. A smart DBA isn't going to do any such thing.
>>> If you go around deleting unknown files you deserve everything you get.
>>> Especially if you are in the middle of a PostgreSQL cluster tree.
>>
>> Couldn't some application trigger this problem regularly (Say, once a 
>> day while
>> importing new data), and therefore create an ever increasing number of 
>> empty
>> files that you can't get rid of without backup,reinit and restore?
> 
> No, the old empty files would get reused if the relation grows again. 
> And they would get deleted if you truncate or drop the relation.
Ah, sorry, I had misunderstood that point. I believed that a new
segment would be created when the relation grows again, and the
empty file would linger around forever...

Thanks for your explaination
greetings, Florian Pflug