On Fri, 2009-05-15 at 22:56 +0900, Fujii Masao wrote: > OK, I probably understood your point. The timeline history files whose > timeline ID is larger than that of an oldest backup must not be deleted > from the archive. On the other hand, the smaller or equal one can be > deleted. Not all history files are necessary. So, if we don't keep older > backup, we probably can delete all files in the archive before > pg_start_backup(). > Is my understanding right?
Heikki is right in one sense: if you do pg_start_backup() then for *that* backup you do not need earlier files. However, as you have pointed out, if you have *multiple* backups then deleting history files may cause problems with an earlier backup. It's standard practice to have >1 backup, so there is potential for error and minimum is we must document that. Rather than explaining the problem and the rules by which we can work out exactly which history files to keep, I think it is safer to say that we must keep all history files. -- Simon Riggs www.2ndQuadrant.com PostgreSQL Training, Services and Support -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
