On Fri, Oct 3, 2014 at 06:08:47PM +0200, Marco Nenciarini wrote: > >> Any comment will be appreciated. In particular I'd appreciate comments > >> on correctness of relnode files detection and LSN extraction code. > > > > I didn't look at it in detail, but one future problem comes to mind: > > Once you implement the server-side code that only sends a file if its > > LSN is higher than the cutoff point that the client gave, you'll have to > > scan the whole file first, to see if there are any blocks with a higher > > LSN. At least until you find the first such block. So with a file-level > > implementation of this sort, you'll have to scan all files twice, in the > > worst case. > > > > It's true. To solve this you have to keep a central maxLSN directory, > but I think it introduces more issues than it solves.
The central issue Heikki is pointing out is whether we should implement a file-based system if we already know that a block-based system will be superior in every way. I agree with that and agree that implementing just file-based isn't worth it as we would have to support it forever. So, in summary, if you target just a file-based system, be prepared that it might be rejected. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + Everyone has their own god. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
