Re: Hard limit on WAL space used (because PANIC sucks)

On 06.06.2013 17:00, Heikki Linnakangas wrote:
> A more workable idea is to sprinkle checks in higher-level code, before
> you hold any critical locks, to check that there is enough preallocated
> WAL. Like, at the beginning of heap_insert, heap_update, etc., and all
> similar indexam entry points.

Actually, there's one place that catches most of these: LockBuffer(..., 
BUFFER_LOCK_EXCLUSIVE). In all heap and index operations, you always 
grab an exclusive lock on a page first, before entering the critical 
section where you call XLogInsert.

That leaves a few miscellaneous XLogInsert calls that need to be 
guarded, but it leaves a lot less room for bugs of omission, and keeps 
the code cleaner.

- Heikki