On Sat, Jan 22, 2022 at 12:17 AM Robert Haas <robertmh...@gmail.com> wrote: > > On Fri, Jan 21, 2022 at 8:40 AM Shruthi Gowda <gowdas...@gmail.com> wrote: > > From what I see in the code, template0 and postgres are the last > > things that get created in initdb phase. The system OIDs that get > > assigned to these DBs vary from release to release. At present, the > > system assigned OIDs of template0 and postgres are 13679 and 13680 > > respectively. I feel it would be safe to assign 16000 and 16001 for > > template0 and postgres respectively from the unpinned object OID range > > 12000 - 16383. In the future, even if the initdb unpinned objects > > reach the range of 16000 issues can only arise if initdb() creates > > another system-created database for which the system assigns these > > reserved OIDs (16000, 16001). > > It doesn't seem safe to me to rely on that. We don't know what could > happen in the future if the number of built-in objects increases. > Looking at the lengthy comment on this topic in transam.h, I see that > there are three ranges: > > 1-9999 manually assigned OIDs > 10000-11999 OIDs assigned by genbki.pl > 12000-16384 OIDs assigned to unpinned objects post-bootstrap > > It seems to me that what this comment is saying is that OIDs in the > second and third categories are doled out by counters. Therefore, we > can't know which of those OIDs will get used, or how many of them will > get used, or which objects will get which OIDs. Therefore, I think we > should go back to the approach that you were using for template0 and > handle both that database and postgres using that method. That is, > assign an OID manually, and make sure unused_oids knows that it should > be counted as already used.
Agree. In the latest patch, the template0 and postgres OIDs are fixed to unused manually assigned OIDs 4 and 5 respectively. These OIDs are no more listed as unused OIDs. Regards, Shruthi KC EnterpriseDB: http://www.enterprisedb.com
v13-0001-pg_upgrade-perserve-database-OID-patch.patch
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