Hi! I'm Alexander from DataGrip.
We actively use xmin's from pg_catalog tables to incrementally
synchronize our database model.
We have a small number of users that do not have xmin in pg_database
(we've asked them to try `select xmin from pg_database` and got
`column xmin does not exist`).
There is an old ticket https://youtrack.jetbrains.com/issue/DBE-7588
(at that time there was no real need in that xmin so we just removed
it)
Now xmins are back and so are the problems.
The most recent report is about version `PostgreSQL 12.4 (Ubuntu
12.4-1.pgdg18.04+1) on x86_64-pc-linux-gnu, compiled by gcc (Ubuntu
7.5.0-3ubuntu1~18.04) 7.5.0, 64-bit`
How can that happen that there is no xmin in pg_database?
Is it a normal behaviour and that is configurable? Or is this a kind
of data corruption?
Can that happen to other tables?
I haven't been able to find answers myself, so I'm asking for help :)
Thanks in advance