Re: Defaulting wal_sync_method to fdatasync on Linux for 9.1?

Josh Berkus <josh@agliodbs.com> writes:
> On 11/16/10 12:39 PM, Greg Smith wrote:
>> I want to next go through and replicate some of the actual database
>> level tests before giving a full opinion on whether this data proves
>> it's worth changing the wal_sync_method detection.  So far I'm torn
>> between whether that's the right approach, or if we should just increase
>> the default value for wal_buffers to something more reasonable.

> We'd love to, but wal_buffers uses sysV shmem.

Well, we're not going to increase the default to gigabytes, but we could
very probably increase it by a factor of 10 or so without anyone
squawking.  It's been awhile since I heard of anyone trying to run PG in
4MB shmmax.  How much would a change of that size help?

            regards, tom lane