>>> On Mon, Sep 3, 2007 at 11:57 AM, in message <20070903095749.5045211b@xxxxxxxxxxxxxxxxxxxxxx>, Shawn <postgres@xxxxxxxxxxxxxxx> wrote: > Also it runs a lot faster by itself Given the context of the run, there is a possibility that a checkpoint tends to fall at this point in the script because you're filling your WAL files. There is a known issue (which people have been working on fixing in 8.3) which causes the checkpoint to push a lot of pages to the disk and then wait on physical writes. If the VACUUM ANALYZE doesn't turn up anything useful, an interesting experiment would be to run your script with these modifications to your postgresql.conf file: bgwriter_lru_percent = 20.0 # 0-100% of LRU buffers scanned/round bgwriter_lru_maxpages = 200 # 0-1000 buffers max written/round bgwriter_all_percent = 10.0 # 0-100% of all buffers scanned/round bgwriter_all_maxpages = 600 # 0-1000 buffers max written/round Don't leave these in effect permanently without close attention to the overall impact. These settings have worked well for us, but are likely not to work well for everyone. -Kevin ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings
