Re: Add last_commit_lsn to pg_stat_database

Hi James,

Thanks for the updated patch. I don't have a clear opinion on the
feature and whether this is the way to implement it, but I have two
simple questions.

1) Do we really need to modify RecordTransactionCommitPrepared and
XactLogCommitRecord to return the LSN of the commit record? Can't we
just use XactLastRecEnd? It's good enough for advancing
replorigin_session_origin_lsn, why wouldn't it be good enough for this?


2) Earlier in this thread it was claimed the function returning the
last_commit_lsn is STABLE, but I have to admit it's not clear to me why
that's the case :-( All the pg_stat_get_db_* functions are marked as
stable, so I guess it's thanks to the pgstat system ...


regards

-- 
Tomas Vondra
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