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Re: svn commit: r934008 - /subversion/trunk/subversion/libsvn_subr/sqlite.c

From: C. Michael Pilato <cmpilato_at_collab.net>
Date: Wed, 14 Apr 2010 12:47:41 -0400

Philip Martin wrote:
> philip_at_apache.org writes:
>
>> Author: philip
>> Date: Wed Apr 14 16:35:11 2010
>> New Revision: 934008
>>
>> URL: http://svn.apache.org/viewvc?rev=934008&view=rev
>> Log:
>> * subversion/libsvn_subr/sqlite.c
>> (svn_sqlite__hotcopy): Use the SQLite backup interface if available.
>>
>> Modified:
>> subversion/trunk/subversion/libsvn_subr/sqlite.c
>
> The backup method works but is measurably slower in my tests than than
> the plain copy under a lock; the benefit should be better concurrency.
>
> I don't know which is better: the faster hotcopy that blocks writers
> or the slower hotcopy that allows writers to progress? At the moment
> it's a compile time decision based on the version of SQLite but that's
> not a good way to decide whether we should be using this feature. I
> think it's too obscure to make it configurable on a per-repository
> basis so I don't really know what we should do.

The nature of a "hot copy" is generally such that the copied thing isn't
"unavailable" by most definitions thereof. Not sure that write-locking the
repository really counts as "hot". :-)

-- 
C. Michael Pilato <cmpilato_at_collab.net>
CollabNet   <>   www.collab.net   <>   Distributed Development On Demand

Received on 2010-04-14 18:48:12 CEST

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