Tom Lane wrote: >> While playing around with ANALYZE on foreign tables, I noticed >> that the row count estimate for foreign scans is still >> initialized to 1000 even if there are statistics for the >> foreign table. I think that this should be improved.
>> The attached patch illustrates my suggestion. > I don't think this is appropriate; it will just waste cycles because > the FDW will have to repeat the calculations after obtaining a real > estimate of the foreign table size. If we trusted pg_class.reltuples > to be up to date, there might be some value in this. But we don't > trust that for regular tables (cf. plancat.c), and I don't see why > we would do so for foreign tables. > > I think on the whole it's better to abdicate responsibility here and > require the FDW to do something in its GetForeignRelSize function. > It's not like we'd be saving the FDW a lot of code in the (unlikely) > case that this is exactly what it would do anyway. I agree. Yours, Laurenz Albe -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
