Re: Deleting older versions in unique indexes to avoid page splits

пт, 13 нояб. 2020 г. в 00:01, Peter Geoghegan <pg(at)bowt(dot)ie>:

> Attached is v8, which has the enhancements for low cardinality data
> that I mentioned earlier today. It also simplifies the logic for
> dealing with posting lists that we need to delete some TIDs from.
> These posting list simplifications also make the code a bit more
> efficient, which might be noticeable during benchmarking.
>

I've looked through the code and it looks very good from my end:
- plenty comments, good description of what's going on
- I found no loose ends in terms of AM integration
- magic constants replaced with defines
Code looks good. Still, it'd be good if somebody with more experience could
look into this patch.

Question: why in the comments you're using double spaces after dots?
Is this a convention of the project?

I am thinking of two more scenarios that require testing:
- queue in the table, with a high rate of INSERTs+DELETEs and a long
transaction.
Currently I've seen such conditions yield indexes of several GB in size
wil holding less
than a thousand of live records.
- upgraded cluster with !heapkeyspace indexes.

--
Victor Yegorov