Hi Wales 2012/2/27 Wales Wang <wormw...@yahoo.com> wrote: > There are many approach for PostgreSQL in-memory. > The quick and easy way is making slave pgsql run on persistent RAM > filesystem, the slave is part of master/slave replication cluster. > > The fstab and script make RAM file system persistent is below: > Setup: > First, create a mountpoint for the disk : > mkdir /mnt/ramdisk > Secondly, add this line to /etc/fstab in to mount the drive at boot-time. > tmpfs /mnt/ramdisk tmpfs defaults,size=65536M 0 0 > #! /bin/sh > # /etc/init.d/ramdisk.sh > # > > case "$1" in > start) > echo "Copying files to ramdisk" > rsync -av /data/ramdisk-backup/ /mnt/ramdisk/ > echo [`date +"%Y-%m-%d %H:%M"`] Ramdisk Synched from HD >> > /var/log/ramdisk_sync.log > ;; > sync) > echo "Synching files from ramdisk to Harddisk" > echo [`date +"%Y-%m-%d %H:%M"`] Ramdisk Synched to HD >> > /var/log/ramdisk_sync.log > rsync -av --delete --recursive --force /mnt/ramdisk/ > /data/ramdisk-backup/ > ;; > stop) > echo "Synching logfiles from ramdisk to Harddisk" > echo [`date +"%Y-%m-%d %H:%M"`] Ramdisk Synched to HD >> > /var/log/ramdisk_sync.log > rsync -av --delete --recursive --force /mnt/ramdisk/ > /data/ramdisk-backup/ > ;; > *) > echo "Usage: /etc/init.d/ramdisk {start|stop|sync}" > exit 1 > ;; > esac > exit 0 > > you can run it when startup and shutdown and crontabe hoursly. > > Wales Wang
Thank you for the tipp. Making slave pgsql run on persistent RAM filesystem is surely at least a possibility which I'll try out. But what I'm finally after is a solution, where records don't get pushed back to disk a.s.a.p. but rather got hold in memory as long as possible assuming that there is enough memory. I suspect that currently there is quite some overhead because of that (besides disk-oriented structures). -Stefan -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance