File Buffering Questions ...

[Roger Oberholtzer]

On Wed, 2006-06-14 at 08:36 -0500, Ben Duncan wrote:
> Ohhh .. developing an ICE CREAM headache from writing my MVISAM database.
> It's too bad some of the more advance stuff is making sense now, 'cause
> I cannot plead ignorance on mistakes.
> 
> Anway, thought I would run this past the REAL experts.
> 
> When dealing with multiple open/access on the SAME file from within MVISAM module,
> should I share the already allocated cache/buffers for that file, or would it
> be more prudent to allocate each file descriptor it's own set of buffers?
> 
> Each fd will have a minimum cache of 4 - 4K buffers (A node is 4K bytes). There is
> a place in the Super Block to specify "Buffering" for additional allocation of
> buffers.

I gather this is a database app. Why not mmap() the file? The OS does a
great job of managing the cache when you do this. Not sure what MVISAM
is up to. But maybe it offers this as a file access option?

-- 
Roger Oberholtzer

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