Re: when to SQL; RFE's (to dev?)

[Michael Monnerie <m....@zmi.at>]

On Montag, 31. Oktober 2005 03:15 Linda Walsh wrote:
> Still am not sure what size system (or user) db's should trigger
> usage of "SQL".  Any reason why user DB's would hurt performance
> over a system DB using Berkeley format?  Supposing I have no system
> DB and am only using user DB's?  What if it is a small group 3-4
> people? Is it an issue of having to read in the DB with each email /
> user and the system DB might hang around in memory?  Does the system
> DB get some preferential treatment?  I.e. if one user gets 80% of the
> email, will SA operate as though it is using a system DB?

There are so many variables, that you can't tell really. The "DB" format 
is easy to use, as it creates the files itself etc. To use SQL takes 
some effort, but afterwards scales better (I mean 100+ users). For a 
handful of people I guess the difference is peanuts, use what you like. 
As long as your hardware can make it, it doesn't matter.

I use DB until now, with lots of domains and users on several hosts. 
It's not a performance question, but an administrative one, that I will 
switch to SQL soon. I want to offer a webpage for each user to 
configure their own settings. Also, if you use cyrus IMAPd, you don't 
need Linux users anymore, so you need SQL to store personal 
preferences, as the user doesn't exist and therefore has no homedir to 
store the DB.

>     Still not so sure about why "sa-learn" would process emails so
> much more slowly than 2.6x, since for an individual user, it wouldn't
> be accessing a system DB, no?

I guess it's for other reasons to be slower - but does it hurt? For me, 
sa-learn is an automated job, and I don't really care if it takes 1 or 
100 seconds, as long as the machine still runs smoothly. But of course, 
the quicker the better :-)

mfg zmi
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