Re: nested xacts and phantom Xids

Alvaro Herrera <alvherre@dcc.uchile.cl> writes:
> On Mon, Jun 21, 2004 at 10:28:59PM -0400, Tom Lane wrote:
>> Also, rather than labeling each entry individually, it might be better
>> to keep a separate list for each level of transaction.  Then instead of
>> relabeling, you'd just concat the subtrans list to its parent's.  Seems
>> like this should be faster and less storage.

> Right, but it makes harder to detect when a duplicate relcache entry is
> going to be inserted.  Judging from the commentary in the file this is
> an issue.

It's only a minor efficiency hack; don't get too tense about avoiding dups.
(We don't bother to check for dup catcache-inval entries at all...)
The only thing I'd suggest you need to preserve is the business about
invalidating catcache before relcache; again that's just an efficiency
hack, but it seems simple enough to be worth doing.

            regards, tom lane