How to investigate deadlocks

Hello,

One of our clients running our LMS on top of PostgreSQL 13.1 created a
ticket with these messages:

2023-09-30 16:50:50.951 CEST [18117] ERROR:  deadlock detected
2023-09-30 16:50:50.951 CEST [18117] DETAIL:  Process 18117 waits for ShareLock on transaction 150396154; blocked by
process18187.
 
    Process 18187 waits for ShareLock on transaction 150396155; blocked by process 18117.
    Process 18117: fetch hc_d03geb
    Process 18187: fetch hc_d02ben
2023-09-30 16:50:50.951 CEST [18117] HINT:  See server log for query details.
2023-09-30 16:50:50.951 CEST [18117] CONTEXT:  while locking tuple (38,57) in relation "d03geb"
2023-09-30 16:50:50.951 CEST [18117] STATEMENT:  fetch hc_d03geb

The shown PIDs for sure are the ones of the Pos backend proc (on Linux).
Is there any chance to investigate it further?

Thanks

    matthias

-- 
Matthias Apitz, ✉ guru@unixarea.de, http://www.unixarea.de/ +49-176-38902045
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