Re: MemopMemmmmo

[Harry Thijssen]

> Date: Sat, 17 Mar 2012 13:44:14 +0000
> From: John Darrington
> To: address@hidden
> Subject: MemopMemmmmo"
>
> I've noticed that it's very easy to cause PSPP to crash with
> "memory exhausted" by trying to run a procedure such as MEANS
> or EXAMINE with a categorical variable which contains many distinct
> values.
>
> Clearly running such a procedure is stupid thing to do, and probably
> means the user doesn't know what he's doing.  However it could also
> be an innocent mistake (like a wrong click in the gui).  But whatever,
> .. I think it's bad when a wrong input causes a crash.
>
> I think it might improve matters if we made the function
> settings_get_workspace_cases a little more intelligent.  This function
> returns  a recommendation on how much memory a procedure can malloc.
> At very least, it shouldn't recommend mallocing more memory than is
> currently available in core.  Maybe it should also be somewhat adaptive in
> the sense that it doesn't return more than 50% of the available memory.
>
> What do you think?
>
> J'

A crash should be avoided anyhow, so every change to avoid a crash is
good. What will be the impact of the reduced memory allocation?
Slowing down PSPP?
I can image this will also happen on a (virtual) PC with limited
memory. In this case this can be triggered by a user who doesn't know
the precise hardware of here/his computer.
Maybe a warning in the output too?

Have fun