Re: [Firebird-devel] Delete by pool and parent_redirect

[Alexander p. <pes...@ma...>]

On Monday 27 April 2009 12:29:16 Vlad Khorsun wrote:
> > On Friday 24 April 2009 16:31:00 Vlad Khorsun wrote:
> >> I see two options :
> >>
> >> a) disable "parent_redirect". It will make HEAD work almost as 2.1,
> >> AFAIU
> >>
> >> b) rework "parent_redirect" to request medium sized memory chunks from
> >> parent pool (say 4-8KB) and use it to allocate memory for immediate
> >> callers. When such pool is freed it (pool) have to deallocate from
> >> parent pool much less number of memory blocks.
> >>
> >> Opinions ?
> >
> > In v.3.0 we plan to use vulcan's memory allocator. Looks like it can
> > behave better, specially under MT load. Therefore I suggest to choose
> > option (a) - sooner of all it's no use wasting time with MemoryPool
> > optimization. What about memory - it's cheap :)
>
>     I have concern with this simple solution. Before v2.5 we allocated some
> pools from database pool - in DFW, DYN (i don't care about it much as it is
> short lived temporary pools) and in CMP which is more questionable, i
> think.

Did you take a look - how did it 1.5 where we had no "parent_redirect" ?

>     Disable "parent_redirect" in CMP pool (this is request's pool) will
> make every request allocate 64KB at least (despite of real needs). Is it
> what we want ?

On the one hand, memory is cheap today. On the other - do we have some 
statistics about it? If we really use not more than Xkb (where X is much than 
64) per typical request, may be request single medium-size memory chunk of 
Xkb from parent and later continue with normal operation? It will be 
something like inline storage in arrays.