Re: patch review : Add ability to constrain backend temporary file space

2011/6/2 Mark Kirkwood <mark(dot)kirkwood(at)catalyst(dot)net(dot)nz>:
> On 01/06/11 09:24, Cédric Villemain wrote:
>> * I am not sure it is better to add a fileSize like you did or use
>> relationgetnumberofblock() when file is about to be truncated or
>> unlinked, this way the seekPos should be enough to increase the global
>> counter.
>>
>
> The temp files are not relations so I'd have to call stat I guess. Now
> truncate/unlink can happen quite a lot (e.g hash with many files) and I
> wanted to avoid adding too many library calls to this code for performance
> reasons, so on balance I'm thinking it is gonna be more efficient to
> remember the size in the Vfd.

I am not sure temporary relation are truncated. I have not checked
right now, but IIRC, we don't need to truncate it. And I believe it
would defeat the log_temp feature because log_temp is done on
FileClose() only.

If we are to add a field in struct vfd to keep the filesize then some
optimization may happens for logging too....