Re: [HACKERS] aggregation memory leak and fix

> 
> > No apologies necessary.  Glad to have someone digging into that area of
> > the code.  We will gladly apply your patches to 6.5.  However, I request
> > that you send context diffs(diff -c).  Normal diffs are just too
> > error-prone in application.   Send them, and I will apply them right
> > away.
> >  
> Context diffs attached.  This was due to my ignorance of diff.  When I
> made the other files, I though "hmm, these could be difficult to apply
> if the code has changed a bit, wouldn't it be good if they included a
> few lines before and after the fix".  Now I know "-c".

I have had to back out the nodeAgg.c part of the patch.  The rest looks
OK, partly because it is dealing with freeing expression context, and
partly because I don't understand it all.

The nodeAgg.c part of the patch is clearly trying to free memory
allocated as intermediate parts of the expression, and has to be solved
by a more general solution as I discussed.

If you look in backend/utils/adt/*.c, you will see lots of intermediate
memory allocated.  The allocacations as part of the *in/*out functions
are not a problem, because they are called only in other areas, and are
freed, but the other ones are probably not free'ed until statement
termination.  I may need to specifically put those pfree's in their own
context, and free them on tuple completion.

I am waiting to hear what others say about my ideas.  Feel free to keep
digging.


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