Re: Use of non-restart-safe storage by temp_tablespaces

Andres Freund wrote:

> FWIW, allowing UNLOGGED tables, rather than just TEMPORARY ones,
> increases the complexity of that project noticeably. For TEMPORARY you
> basically don't need to do much but to recreate the structure inside the
> tablespace at start - fairly simple. But for UNLOGGED you need to find
> a way to recreate the relevant file and init forks - otherwise we might
> not notice what needs to be reset at a crash restart, and we might error
> out when executing selects etc. and then the table's not there.
> Presumably recreating files & init forks that at first table access is
> doable, but it's not entirely trivial to do locking wise.

I was thinking that you could create the init fork for each unlogged
table in a permanent tablespace (probably the default one for the
database).

FWIW I don't think calling these tablespaces "temporary" is the right
word. It's not the tablespaces that are temporary. Maybe "evanescent".
Also, do we really need it to be a keyword after CREATE? We could put
the option in the WITH clause of CREATE TABLESPACE instead.

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Álvaro Herrera https://www.2ndQuadrant.com/
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