Excerpts from Kohei Kaigai's message of mar jul 05 11:46:06 -0400 2011: > > On Tue, Jul 5, 2011 at 10:49 AM, Alvaro Herrera > > <alvhe...@commandprompt.com> wrote: > > > Excerpts from Robert Haas's message of mar jul 05 10:19:18 -0400 2011: > > > > > >> Hmm, OK. I guess what I'm not sure about is - how much should we > > >> worry about the fact that this creates several more shared (and > > >> therefore nailed?) system catalogs? Anyone have an opinion on that? > > > > > > "Several"? That would worry me, given that we currently have a small > > > number (eight currently). If it's just one more, I don't think it's > > > such a big deal. I'm not sure what you mean by nailed though -- I mean, > > > for example pg_shdescription is shared but not nailed in the rd_isnailed > > > sense of the word, AFAICS. > > > > Well, right now the patch has pg_shseclabel, and its index, plus a > > toast table and a toast index. Not sure why we want/need the toast > > table & index there, but the patch has 'em as of now. > > > As a common belief, TEXT is a variable length data type, so pg_shseclabel > need to have its toast table. However, I don't expect the label field get > represented as a reference to external pointer, because average length of > security context is about 40-60 bytes much less than the threshold to > launch toast_save_datum(). > Do I need to remove these toast table & index?
We don't have toast tables for pg_database and so on, for example, which means that datacl cannot go over a few hundred bytes long. I think it makes sense to not have toast tables for pg_shseclabel. Keep in mind that the label might be compressed before it's stored out of line, which gives you quite a bit of actual space. If a security context is over 5000 bytes in length I think you're in trouble :-) -- Álvaro Herrera <alvhe...@commandprompt.com> The PostgreSQL Company - Command Prompt, Inc. PostgreSQL Replication, Consulting, Custom Development, 24x7 support -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers