Re: Performance lossage in checkpoint dumping

> 3. Blind write is gratuitously inefficient: it does separate open,
> seek, write, close kernel calls for every request.  This was the right
> thing in 7.0.*, because backends relatively seldom did blind writes and
> even less often needed to blindwrite multiple pages of a single relation
> in succession.  But the typical usage has changed a lot.
> 
> 
> I am thinking it'd be a good idea if blind write went through fd.c and
> thus was able to re-use open file descriptors, just like normal writes.
> This should improve the efficiency of dumping dirty buffers during
> checkpoint by a noticeable amount.

I totally agree the current code is broken.  I am reading what you say
and am thinking, "Oh well, we lose there, but at least we only open a
relation once and do them in one shot."  Now I am hearing that is not
true, and it is a performance problem.

This is not a total surprise.  We have that stuff pretty well
streamlined for the old behavour.  Now that things have changed, I can
see the need to reevaluate stuff.

Not sure how to handle the beta issue though.

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