On 16/08/2009 9:06 PM, NTPT wrote:
So I suggest we should have "random_page_cost" and "Sequential_page_cost" configurable on per tablespace basis.
That strikes me as a REALLY good idea, personally, though I don't know enough about the planner to factor in implementation practicalities and any cost for people _not_ using the feature.
2: Many of that RSD devices are not so much reliable (power outage in ramdisk, weak auxillarity battery in i-ram like devices, block "wear out" in SSD).
[snip]
ie read from fast tablespace, write to both fast and slow, reconstruct fast from slow if appropriate.
This can probably be done as well or better at the OS block layer, using device-mapper or the `md' driver (on Linux).
What'd be interesting, though, would be if Pg had support for auto-rebuilding indexes and (if/when explicit support is added) materialized views if it finds the backing files are missing. This would be helpful for such transient devices as RAM disks if you didn't want to bother having physical storage backing it.
-- Craig Ringer -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
