On Tue, May 10, 2011 at 3:35 AM, Leonardo Francalanci <m_li...@yahoo.it> wrote: >> Yes, that seems like a very appealing approach. There is plenty of >> bit-space available in xinfo, and we could reserve a bit each for >> nrels, nsubxacts, and nmsgs, with set meaning that an integer count of >> that item is present and clear meaning that the count is omitted from >> the structure (and zero). This will probably require a bit of tricky >> code reorganization so I think it should be done separately from the >> main patch. > > Ok, I'll try and send a patch with this change only. > BTW xinfo is 32 bit long, but I think only 2 bits are used right now? > I think I can make it a 8 bits, and add another 8 bits for nrels, > nsubxacts, and nmsgs and the new thing. That should save > another 2 bytes, while leaving space for extention. Or we can make > it a 8 bits only, but only 2 bits would be left "empty" for future > extentions; I don't know if we care about it...
I don't think making xinfo shorter will save anything, because whatever follows it is going to be a 4-byte quantity and therefore 4-byte aligned. -- 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
