On Sat, May 4, 2013 at 5:53 AM, Yang Zhang <yanghatespam@xxxxxxxxx> wrote:
--
Michael
Yeah, I know that indexes for unlogged tables are unlogged. I was
just wondering if you could do this for logged tables. (Safely, such
that on crash recovery WAL replay won't throw up, these can be omitted
from base backups, etc.)
No, you cannot create unlogged indexes on logged tables. An unlogged tables is
truncated when a server starts after a crash, and so are its indexes that become
empty by default. But having an unlogged index on a logged table would mean that
truncated when a server starts after a crash, and so are its indexes that become
empty by default. But having an unlogged index on a logged table would mean that
you would need to truncate and regenerate the index after a crash as the data of
the normal table is still here, what would impact the performance boot of the server.
Do you have a particular use-case in mind? I cannot see advantages directly
advantages in having an unlogged index on a logged table...
the normal table is still here, what would impact the performance boot of the server.
Do you have a particular use-case in mind? I cannot see advantages directly
advantages in having an unlogged index on a logged table...
Regards,
Michael
