Re: [exim] Tools for SQL export to CDB

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Auteur: David Saez Padros
Date:  
CC: exim users
Sujet: Re: [exim] Tools for SQL export to CDB
Hi !!

>> the problem with sqlite and also with dbm databases is that writing to
>> the database locks all database (read/write) and only one process can
>> update the database (only one write lock) and while the database is
>> being updated no process can read it, so frequent updates make reading
>> the database slower. As cdb is read only no locking is required.
>
> Agreed, but have you actually measured it? SQLite updating is really
> fast, even for hundreds of transactions per second (my usage test here).
> That's why I mentioned a comparison... guesses aren't necessarily
> worth much :)


no, i never have measured it, nor i never see a good comparision of
both databases. What i'm sure is that cdb is faster on reads than
sqlite for many reasons (sql command parsing, file locking, ...)
but maybe the read/write speed compensates for the 5 minutes whole
database rebuild (some day in the near future i will try to measure
it, but by now the cpu load for all of it is good for me)

--
Best regards ...

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