Re: Advice on MyXactMade* flags, MyLastRecPtr, pendingDeletes and lazy XID assignment

"Florian G. Pflug" <fgp(at)phlo(dot)org> writes:
> And I'm quite tempted to not flush the XLOG at all during ABORT, and to
> only force synchronous commits if one of the to-be-deleted files is
> non-temporary.

+1 on the first, but -1 on the second, because we'd have to track
whether deleted files are temp or not ... it's very unclear that it'd
be worth the trouble.

> OTOH, it'd allow aynchronous commits for transactions that created
> temporary tables.

It'd be for xacts that *dropped* temp tables, no? I'm not sure that
is a performance-critical path --- probably it more usually gets done
after the client's already disconnected.

>> The only way we could make this more robust is if we could have
>> WAL-before-data rule for file *creation*, but I think that's not
>> possible given that we don't know what relfilenode number we will use
>> until we've successfully created a file.

> It seems doable, but it's not pretty. One possible scheme would be to
> emit a record *after* chosing a name but *before* creating the file,

No, because the way you know the name is good is a successful
open(O_CREAT).

regards, tom lane