Re: long running transactions

Tobias Brox <tobias@nordicbet.com> writes:
> (gdb) bt
> #0  0xb7c599f8 in select () from /lib/tls/libc.so.6
> #1  0x08253c53 in pg_usleep ()
> #2  0x0812ee93 in vacuum_delay_point ()
> #3  0x0812f2a5 in lazy_vacuum_rel ()
> #4  0x0812ef7b in lazy_vacuum_rel ()
> #5  0x0812b4b6 in vac_update_relstats ()

That doesn't look particularly blocked, and if you are seeing
reads/writes too, then it's doing something.

> It seems stuck, has had the same transid for a long while, and the
> number of undeletable dead rows in our tables are increasing.

Perhaps you have overly aggressive vacuum cost delay settings?

            regards, tom lane