New FreeBSD package system (a.k.a. Daemon Package System (dps))

[Bert JW Regeer]

On May 12, 2007, at 5:14 AM, Philippe Laquet wrote:

> Stanislav Sedov a écrit :
>> On Fri, 11 May 2007 02:10:05 +0200
>> Ivan Voras <ivoras at fer.hr> mentioned:
>>
>>
>>> - I think it's time to give up on using BDB+directory tree full  
>>> of text
>>> files for storing the installed packages database, and I propose  
>>> all of
>>> this be replaced by a single SQLite database. SQLite is public  
>>> domain
>>> (can be slurped into base system), embeddable, stores all data in a
>>> single file, lightweight, fast, and can be used to do fancy  
>>> things such
>>> as reporting.
>>>
>>
>> What is the reason to use SQL-based database? You'll perform direct
>> queries to database? The packaging system is for ordinal users,  
>> not sql
>> geeks, so they should not have to use sql for managing packages. So a
>> simple set of hashes will suffer or needs. I agree with Julian  
>> that we
>> should have a backup of packaging database in plain text format, and
>> utility to rebuild it. This way we can always restore the database if
>> something goes wrong. Furhtermore, that should not make a great  
>> impact
>> on performance, since we don't have to rebuild it every day.
>>
> I agree with Stan ;)
>
> "fast and improved" package utilities uses mainly some indexed  
> berkeley DB combined with flat files, aren't they? I, and may be  
> many other FreeBSD users use light systems for efficiency and  
> eaiser management, if we use some database system it will require  
> Disk Space, ressources for the DB to run, dependencies and so on...  
> And we also may be exposed to a "that DB is better" war ;)
>

SQLite is compiled inside a program, and as such does not require any  
resources other than one file handle and some CPU time when querying.  
The file is stored on disk, and requires no separate process to be  
running to query. Maybe I misunderstood what you were trying to say.  
SQLite will require less resources than flat text files, since SQLite  
is a one time open then process, instead of what is currently  
happening, having to open and close hundreds of files depending on  
how many ports are installed. With this regard, SQLite is like BDB.  
Where SQLite uses standards compliant SQL statements to get data.

>
>> --
>> Stanislav Sedov
>> ST4096-RIPE
>>
>

I am able to understand many of the gripes with using a databases,  
and have to import yet another code base into the FreeBSD base,  
however as one of the young ones, and knowing sed/awk/grep and SQL, I  
prefer SQL over having to process hundreds of text files using text  
processing tools. It saddens me each time I run one of the pkg_*  
tools that needs to parse the flat file structure since it takes so  
long. I have friends running Ubuntu and their apt-get returns results  
much faster.

In a world where hard drives are becoming more reliable, and are  
automatically relocating sectors that go bad, do we really have to  
worry about database corruption as much? I feel that many of the  
fears that are being put forward will do harm to a text based  
"storage" system as well. If one block drops out, it can cause tools  
to not be able to parse the files. Create a backup copy of the  
database after each successful transaction? There are ways to battle  
data corruption.

Using BDB is not an real option either. I can not even count the  
amount of times that the BDB database that portupgrade created has  
become corrupt because I accidently ran two portupgrades at the same  
time, or even remembered that I did not want to upgrade something and  
hit Ctrl+C. The experience I got from running SVN with BDB as the  
back-end database to store my data, I say no thanks. In that case I  
would much rather stick with the flat text files than go with a  
database.

Bert JW Regeer