Re: Pg_upgrade and toast tables bug discovered

>> Uh, I guess we could write some code that iterates over all tables and
>> finds the tables that should have TOAST tables, but don't (because
>> binary-upgrade backend mode suppressed their creation), and adds them.
>>
>> However, that would be a lot of code and might be risky to backpatch.
>> The error is so rare I am not sure it is worth it. I tried to create
>> the failure case and it was very difficult, requiring me to create the
>> problem table first, then some dummy stuff to get the offsets right so
>> the oid would collide.
>>
>> Based on the rareness of the bug, I am not sure it is worth it, but if
>> it is, it would be something only for 9.4 (maybe) and 9.5, not something
>> to backpatch.
>
> Another idea would be to renumber empty toast tables that conflict
> during new toast table creation, when in binary upgrade mode. Since the
> files are always empty in binary upgrade mode, you could just create a
> new toast table, repoint the old table to use (because it didn't ask for
> a specific toast table oid because it didn't need one), and then use
> that one for the table that actually requested the oid. However, if one
> is a heap (zero size), and one is an index (8k size), it wouldn't work
> and you would have to recreate the file system file too.
>
> That seems a lot more localized than the other approaches.

To me, that sounds vastly more complicated and error-prone than
forcing the TOAST tables to be added in a second pass as Andres
suggested.

But I just work here.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company