Re: Deleting older versions in unique indexes to avoid page splits - Mailing list pgsql-hackers

From Victor Yegorov
Subject Re: Deleting older versions in unique indexes to avoid page splits
Date
Msg-id CAGnEboi3hUF04DNHBTyjdNypeiSHTY4zkUJHyWkZEWY+henu2Q@mail.gmail.com
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In response to Re: Deleting older versions in unique indexes to avoid page splits  (Peter Geoghegan <pg@bowt.ie>)
Responses Re: Deleting older versions in unique indexes to avoid page splits  (Peter Geoghegan <pg@bowt.ie>)
List pgsql-hackers
пт, 13 нояб. 2020 г. в 00:01, Peter Geoghegan <pg@bowt.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

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