(2012/03/13 15:53), Shigeru HANADA wrote: > (2012/03/12 19:21), Etsuro Fujita wrote: >> According to the following documentation on IterateForeignScan() in >> 50.2. Foreign Data Wrapper Callback Routines, I have created a patch to >> support the error handling in file_fdw. Please find attached a patch.
> Interesting. This patch could be applied cleanly, and it catches first > record which violates NOT NULL constraint. I have some comments for the > patch. Thank you for the review. > I worry performance degradation caused by checking NOT NULL constraints > for every row, though such overhead might be hidden by disk I/O. Do you > have any result of performance testing? Users might want to disable NOT > NULL checking for already-validated files. I don't have any numbers for now. OK I'll check it. > In addition to performance issue, IMHO exporting > ExecBuildSlotValueDescription needs more consideration. Have you > examined calling ExecConstraints instead of copying NOT NULL check > codes? It requires fully-built ResultRelInfo, and it also checks CHECK > constraints which have not been supported on foreign tables, but it > seems the standard way to apply constraints on a tuple. Yes, I thought the use of ExecConstraints(). But I feel that it is an overkill. > If you don't > want to check CHECK constraints, another possible idea is to add new > external function ExecNotNull (or something) and move NOT NULL checking > codes from ExecConstraints, and call it from fileIterateForeignScan and > ExecConstraints. I think that it is a good idea. I'll do it at the next version of the patch. > Anyway, please add this patch to Commit Fest App for tracking. > https://commitfest.postgresql.org/action/commitfest_view?id=14 Done. Best regards, Etsuro Fujita -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
