Re: TOAST performance (was Re: [GENERAL] Delete Performance)

> Bruce Momjian <pgman@candle.pha.pa.us> writes:
> > Could we add code to detect a partial write when we recover from one
> > using WAL so we can know if these partial writes are ever
> > happening?
> 
> What's your point?  It clearly *can* happen during power-failure
> scenarios.  All the monitoring in the world won't disprove that.

What bothers me about this is that we have the original page with the
old data.  It would be nice if we could write the new page in a
different location, make the new page active and recycle the old page at
some later time.

We are storing the pre-page image in WAL, but it seems like a waste
because we already have a pre-image.  It is just that we are overwriting
it.

--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
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