Dilip Kumar <dilipbal...@gmail.com> writes: > On Tue, 19 Jan 2021 at 6:28 PM, Amit Kapila <amit.kapil...@gmail.com> wrote: >> Won't it be safe because we don't align individual attrs of type >> varchar where length is less than equal to 127?
> Yeah right, I just missed that point. Yeah, the minimum on biggest_size has nothing to do with alignment decisions. It's just a filter to decide whether it's worth trying to toast anything. Having said that, I'm pretty skeptical of this patch: I think its most likely real-world effect is going to be to waste cycles (and create TOAST-table bloat) on the way to failing anyway. I do not think that toasting a 20-byte field down to 18 bytes is likely to be a productive thing to do in typical situations. The given example looks like a cherry-picked edge case rather than a useful case to worry about. IOW, if I were asked to review whether the current minimum is well-chosen, I'd be wondering if we should increase it not decrease it. regards, tom lane