On Tue, Jun 12, 2018 at 6:31 PM, Scott Stroupe <sstroupe@xxxxxxxxxx> wrote: > According to the documentation[1], pg_lsn is a 64-bit integer that's printed as two hex numbers separated by a slash, e.g. 68/1225BB70. Is there a way to get the 64-bit integer in a common numeric representation instead of the peculiar hex-slash-hex representation? ... > [1] https://www.postgresql.org/docs/current/static/datatype-pg-lsn.html Quoting your own [1] ref :"Two LSNs can be subtracted using the - operator; the result is the number of bytes separating those write-ahead log locations." You can try substraction from an arbitrary origin ( pg_lsn('0/0') seems nice, as arbitrary as Greenwich meridian ), and it worked for me in select pg_lsn('68/1225BB70') , pg_lsn('0/0') , pg_lsn('68/1225BB70') - pg_lsn('0/0') , to_hex((pg_lsn('68/1225BB70') - pg_lsn('0/0'))::bigint) ; ( http://sqlfiddle.com/#!17/9eecb/16272 ) Reconstructing via simple addition does not work, but you can do division, modulus, double to_hex, join with '/', cast to pg_lsn if you like. Francisco Olarte.
