Re: Performance degradation of REFRESH MATERIALIZED VIEW

Hi,

I took a look at this today, as I committed 39b66a91b back in January. I 
can reproduce the issue, with just 1M rows the before/after timings are 
roughly 480ms and 620ms on my hardware.

Unfortunately, the v3 patch does not really fix the issue for me. The 
timing with it applied is ~610ms so the improvement is only minimal.

I'm not sure what to do about this :-( I don't have any ideas about how 
to eliminate this overhead, so the only option I see is reverting the 
changes in heap_insert. Unfortunately, that'd mean inserts into TOAST 
tables won't be frozen ...


regards

-- 
Tomas Vondra
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