Hi! Josh Berkus writes:
> Now, if we had an OS which could be convinced to handle caching > differently for different physical devices, then I could see wanting > this setting to be per-tablespace. For example, it would make a lot of > sense not to FS-cache any data which is on a ramdisk or superfast SSD > array. The same with archive data which you expected to be slow and > infrequently accessed on a NAS device. If your OS can do that, while > caching data from other sources, then it would make sense. > > However, I don't know any current OS which allows for this. Does anyone > else? Isn't bypassing the buffer cache exactly what direct I/O is about? Solaris UFS has a "forcedirectio" mount option, AIX JFS2 calls it "dio" and Veritas VxFS uses the "convosync=direct" option to disable caching the content of the filesystem. -- Stefan -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
