Subject: Re: [boost] ACID transactions/flushing/MySQL InnoDB
From: Phil Endecott (spam_from_boost_dev_at_[hidden])
Date: 2009-12-10 18:04:31
Stefan Strasser wrote:
> writing 512 bytes, aligned to 512 bytes, without O_CREAT, when the file
> already exists, brings the desired results
> 2 seconds with much less disk usage.
> that's some set of conditions.
I would be interested to know how this compares to mmapping the file
and then writing to memory and calling msync().
I while ago I did some work on a transactional persistent object
library for "write mostly" data. Since it didn't need to support
efficiently erasing or modifying existing data it could use a pure log
structure with transactions implemented just by atomically adjusting
the end-of-data offset. I did this all via mmapped files and the
performance seemed good enough, but I never benchmarked it against e.g.
MySQL. Actually it has been on hold since I discovered how badly it
performs over NFS...
Boost list run by bdawes at acm.org, gregod at cs.rpi.edu, cpdaniel at pacbell.net, john at johnmaddock.co.uk