På fredag 02. mai 2014 kl. 00:55:25, skrev David G Johnston < david.g.johns...@gmail.com <mailto:david.g.johns...@gmail.com>>: Andreas Joseph Krogh-2 wrote > I will end up with that only if > all users read all messages, which is not nearly the case.
These observations probably won't help but... You have what amounts to a mathematical "spare matrix" problem on your hands... Is there any way to expire messages so that dimension does not grow unbounded? No, unfortunately... Per-User caching does seem to be something that is going to be needed... Depending on how many users are being tracked would storing the "reader_id" in an indexed array improve matters? " SELECT ... FROM message WHERE NOT (1 = ANY(reader_ids)) ; UPDATE message SET reader_ids = reader_ids || 1 WHERE messageid = ..." I'm not that familiar with how well indexes over arrays work or which kind is needed (i.e. gin/gist). "is_read" is one of many properties being tracked for a message... -- Andreas Jospeh Krogh CTO / Partner - Visena AS Mobile: +47 909 56 963 andr...@visena.com <mailto:andr...@visena.com> www.visena.com <https://www.visena.com> <https://www.visena.com>
