[pfx] Re: [heads up] lmdb 1.0

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On 2026/07/05 13:19, Wietse Venema via Postfix-users wrote:
> Michael Grimm via Postfix-users:
>> Well, I will stick with lmdb 0.9.35 for the time being or migrate
>> to other database formats, instead.
> 
> Way to go if you have that option.

I can see two ways to patch for this in Postfix:

1) Instead of dropping the table, walk a cursor and delete each record 
in place. This is much more expensive than the current method, but I 
think it the cost will still be negligible. The most expensive 
transaction is when you run postmap/ postalias.

The nice thing about this is that it seems to me to be the least 
invasive patch, with as little change as possible. Most of the current 
structure stays the same. Importantly, atomicity is retained in the same 
way that it currently exists. This is also compatible with lmdb 0.9.x.

An example patch is attached (not sure if the mailing list allows 
attachments).

2) Alternatively, create a new table in a temp file + rename. There 
would be more code involved for this, and a temp file (if you want to do 
this securely, and not with a predictable name) introduces all kinds of 
file permissions things to take care off across multiple OS's. This, 
too, is compatible with lmdb 0.9.x.

I hope this is useful.

Kind regards,
     Edmund


-- 
Edmund Lodewijks <[email protected]>
TZ: UTC+2 / GMT+2
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