Re: BufFileWrite across MAX_PHYSICAL_FILESIZE boundary

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Tom Lane wrote:
> "Kurt Harriman" <kharriman@greenplum.com> writes:
> > Just noticed buffile.c:292 doesn't look quite right where
> > BufFileDumpBuffer calls FileWrite:
> >      bytestowrite = FileWrite(thisfile, file->buffer, bytestowrite);
> > It looks as though it would write the same data each time the
> > loop is iterated.  Would this be better?
> >      bytestowrite = FileWrite(thisfile, file->buffer + wpos, bytestowrite);
> 
> Yeah, I think you're right.  We've probably not seen this because in
> most usages the buffer is always block-aligned, but it looks possible
> for tuplestore.c to get out of alignment if its concurrent write/read
> feature is exercised just so.  Do you want to try demonstrating the bug
> with a smaller-than-normal setting of MAX_PHYSICAL_FILESIZE?
> 
>             regards, tom lane
> 
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