On 2017-01-23 21:40:53 -0500, Stephen Frost wrote:
> Perhaps I'm missing something here, but with checksums enabled, a hint
> bit update is going to dirty the page (and we're going to write it into
> the WAL and write it out to the heap), no?
No. We only WAL log hint bits the first time a page is modified after a
checkpoint. It's quite likely that you'll set hint bits in the same
checkpoint cycle as the row has been modified last (necessating the hint
bit change). So we can't just pessimize this.
I'm a bit confused about the amount of technically wrong arguments in
this thread.
Greetings,
Andres Freund