Re: [HACKERS] Logical Replication WIP

On 2016-12-13 06:55:31 +0100, Petr Jelinek wrote:
> >> This is a quadratic algorithm - that could bite us... Not sure if we
> >> need to care.  If we want to fix it, one approach owuld be to use
> >> RangeVarGetRelid() instead, and then do a qsort/deduplicate before
> >> actually opening the relations.
> >>
> > 
> > I guess it could get really slow only with big inheritance tree, I'll
> > look into how much work is the other way of doing things (this is not
> > exactly hot code path).
> > 
> 
> Actually looking at it, it only processes user input so I don't think
> it's very problematic in terms of performance. You'd have to pass many
> thousands of tables in single DDL to notice.

Well, at least we should put a CHECK_FOR_INTERRUPTS there. At the moment
it's IIRC uninterruptible, which isn't good for something directly
triggered by the user.  A comment that it's known to be O(n^2), but
considered acceptable, would be good too.

Andres