On Fri, Jun 15, 2012 at 12:22 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Peter Geoghegan <pe...@2ndquadrant.com> writes: >> On 14 June 2012 19:28, Robert Haas <robertmh...@gmail.com> wrote: >>> I thought that doubling repeatedly would be overly aggressive in terms >>> of memory usage. > >> I fail to understand how this sortsupport buffer fundamentally differs >> from a generic dynamic array abstraction built to contain chars. That >> being the case, I see no reason not to just do what everyone else does >> when expanding dynamic arrays, and no reason why we shouldn't make >> essentially the same time-space trade-off here as others do elsewhere. > > I agree with Peter on this one; not only is double-each-time the most > widespread plan, but it is what we do in just about every other place > in Postgres that needs a dynamically expansible buffer. If you do it > randomly differently here, readers of the code will be constantly > stopping to wonder why it's different here and if that's a bug or not.
That could, of course, be addressed by adding a comment. > (And from a performance standpoint, I'm not entirely convinced it's not > a bug, anyway. Worst-case behavior could be pretty bad.) Instead of simply asserting that, could you respond to the specific points raised in my analysis? I think there's no way it can be bad. I am happy to be proven wrong, but I like to understand why it is that I am wrong before changing things. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers