Re: (ITS#8181) LMDB page leaks etc when treating DBs as data

[hyc@symas.com]

juerg.bircher@helmedica.com wrote:
> --_000_D1E06B6B7E2juergbircherhelmedicacom_
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> Hi Howard,
>
> I am new to lmdb. I have been working with lmdb intensively for one month. =
> I really appreciate your great work. Good efficient C code is not always fo=
> und!
> Well I like to follow up on that reported issue.
> I am using multiple databases on the same environment. I was a bit confused=
>   about your statement that most application use never subDBs? I think it is=
>   a great feature that helps to support multiple indexes.
> I ran unintentionally into a related problem as I set the compare function =
> for the main db to an integer based one opposite to the literal compare fun=
> ction which is the default. Therefore when opening a database by its name t=
> he wrong database might be returned as the integer compare function might t=
> hink names are equal as only 96 bits (in my function) are compared. So the =
> compare function only compares the prefix of the database names!
> Maybe the database meta should be kept in a private space. But I also agree=
>   on your statement to keep things simple. I solved the problem by never usi=
> ng the main db so under no circumstances the database meta is corrupted. I =
> think the price paid for having only named databases is very cheap as I ope=
> n databases at startup and keep the database index (dbi).

Thanks for the feedback. Yes, this is the best practice - if you're using 
named databases, you should not use the main DB. (Or just make sure you don't 
create name collisions.)

-- 
   -- Howard Chu
   CTO, Symas Corp.           http://www.symas.com
   Director, Highland Sun     http://highlandsun.com/hyc/
   Chief Architect, OpenLDAP  http://www.openldap.org/project/