[ZODB-Dev] minimizing the need for database packing

Dieter Maurer dieter at handshake.de
Thu Jan 3 13:11:29 EST 2008


Jim Fulton wrote at 2008-1-2 13:32 -0500:
> ...
>> The old "pack" code acquires the "commit" lock at the start
>> of the "copyRest" (copy transactions after pack time) phase
>> and releases it only every 20 "copyOne" calls for the duration
>> of one "copyOne".
>
>
>OK. I don't know what you mean by the "finish test".

A lock needs to be held at the end of "copyRest" until
the state is changed (i.e. "Data.fs.pack" is renamed to "Data.fs").
This is the "finish test".

>As I mentioned, the new packing algorithm holds the commit lock much  
>less than the old one does.

Fine.

When we use it, I will have a look whether I still see optimization
potential :-)



-- 
Dieter


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