Fujii Masao wrote: > On Fri, Jan 15, 2010 at 12:50 AM, Bruce Momjian <br...@momjian.us> wrote: > > Looking at the archive_timeout documentation and CheckArchiveTimeout(), > > it appears we force a new xlog file and archive it even if no activity > > has been recorded in the xlog file. ?Is this correct? > > No. CheckArchiveTimeout() doesn't switch WAL files if there is no activity > after the last switch. In fact, though it calls RequestXLogSwitch(), > the switch is skipped in XLogInsert() because we are exactly at the start > of a file in that case. > > But unfortunately checkpoint would be often recorded between each > switches. So the archive_timeout appears to always force a new WAL file.
I have documented that increasing checkpoint_timeout can avoid WAL writes on idle systems with archive_timeout. -- Bruce Momjian <br...@momjian.us> http://momjian.us EnterpriseDB http://enterprisedb.com + If your life is a hard drive, Christ can be your backup. + -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
