The reason for the 2 hits of Xact SLRU is that once for visibility (MVCC) check and another for commit.
Makes sense. Thanks. Now, is the lack of such a detail when looking at pg_stat_slru (for this and the other 6 named caches) an omission by intent or just no one has taken the time to write up what the different caches are holding? I would think a brief sentence for each followed by a link to the main section describing the feature would be decent content to add to the introduction for the view in 28.2.21.
Also, is "other" ever expected to be something besides all zeros?
