On Tue, Nov 16, 2010 at 7:46 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Robert Haas <robertmh...@gmail.com> writes: >> On Tue, Nov 16, 2010 at 5:57 PM, marcin mank <marcin.m...@gmail.com> wrote: >>> Can (should ?) unlogged tables' contents survive graceful (non-crash) >>> shutdown? > >> I don't think so. To make that work, you'd need to keep track of >> every backing file that might contain pages not fsync()'d to disk, and >> at shutdown time you'd need to fsync() them all before shutting down. > > This is presuming that we want to guarantee the same level of safety for > unlogged tables as for regular. Which, it seems to me, is exactly what > people *aren't* asking for. Why not just write the data and shut down? > If you're unlucky enough to have a system crash immediately after that, > well, you might have corrupt data in the unlogged tables ... but that > doesn't seem real probable.
I have a hard time getting excited about a system that is designed to ensure that we probably don't have data corruption. The whole point of this feature is to relax the usual data integrity guarantees in a controlled way. A small but uncertain risk of corruption is not an improvement over a simple, predictable behavior. -- 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
