[ZODB-Dev] PersistentMapping good for large numbers of objects?

[Stefan H. Holek]

What I was thinking about is to use an OOBTree instead of a 
PersistentMapping in a user folder implementation.

So, getUserNames() would effectively mean mybtree.keys()...

Oh well, so much about drop-in scalability. The *real* solution for this 
scenario seems to be LDAP anyway. ;-)

Thanks,
Stefan



--On Donnerstag, 17. Juli 2003 14:36 +0100 Toby Dickenson 
<tdickenson at geminidataloggers.com> wrote:

> On Thursday 17 July 2003 13:36, Stefan H. Holek wrote:
>
>> How slow would mybtree.keys() be in case of 20,000 objects? Slower than
>> with a plain dict or PersistentMapping? Should a separate list be kept,
>> probably, along the lines of BTrees.Length?
>
> A seperate list of 10 byte keys is a 200k object. Every time the list
> changes  it uses up 200k of disk space, and the same amount has to be
> transferred over  the network to every ZEO client. Any change to the list
> will cause a  conflict.
>
> None of that matters if you never change the content of your btree.... do
> you?

--
The time has come to start talking about whether the emperor is as well
dressed as we are supposed to think he is.               /Pete McBreen/