Re: pg_walinspect - a new extension to get raw WAL data and WAL stats

On Fri, Feb 25, 2022 at 6:03 AM Bharath Rupireddy
<bharath.rupireddyforpostgres@gmail.com> wrote:
> Added a new function that returns the first and last valid WAL record
> LSN of a given WAL file.

Sounds like fuzzy thinking to me. WAL records can cross file
boundaries, and forgetting about that leads to all sorts of problems.
Just give people one function that decodes a range of LSNs and call it
good. Why do you need anything else? If people want to get the first
record that begins in a segment or the first record any portion of
which is in a particular segment or the last record that begins in a
segment or the last record that ends in a segment or any other such
thing, they can use a WHERE clause for that... and if you think they
can't, then that should be good cause to rethink the return value of
the one-and-only SRF that I think you need here.

-- 
Robert Haas
EDB: http://www.enterprisedb.com