2011/4/30 Tomas Vondra <t...@fuzzy.cz>: > I've been digging in the sources, and I've noticed the MaxOffsetNumber > is defined (in storage/off.h) like this > > (BLCKSZ / sizeof(ItemIdData)) > > I guess it might be made a bit more precise by subtracting the header > like this > > (BLCKSZ - offsetof(PageHeaderData, pd_linp) / sizeof(ItemIdData)) > > although the difference is negligible (2048 vs 2042 for 8kB pages).
I guess we could do that, but I'm not sure there's much point. It's also not entirely clear that this would actually work out to a win, because of the issues discussed in the "When can/should we prune or defragment?" section of src/backend/access/heap/README.HOT We could probably figure this out with some careful testing, but I'm not sure it's worth the effort. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
