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<H1>Re: [MUD-Dev] Database back ends</H1>
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<LI><em>To</em>: <A HREF="mailto:mud-dev#kanga,nu">mud-dev#kanga,nu</A></LI>
<LI><em>Subject</em>: Re: [MUD-Dev] Database back ends </LI>
<LI><em>From</em>: Kevin Littlejohn <<A HREF="mailto:darius#connect,com.au">darius#connect,com.au</A>></LI>
<LI><em>Date</em>: Thu, 20 Apr 2000 09:13:03 +1000</LI>
<LI><em>Reply-To</em>: <A HREF="mailto:mud-dev#kanga,nu">mud-dev#kanga,nu</A></LI>
<LI><em>Sender</em>: <A HREF="mailto:mud-dev-admin#kanga,nu">mud-dev-admin#kanga,nu</A></LI>
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<PRE>
>>> Greg Underwood wrote
>
> dwacks#saleslogix,com writes:
>
> > My question is: In general how do you feel about using a DB back end and
> > what problems do you see with this.
>
> Basically, as with anything in computers, it's a set of trade-offs. Do you
> want flexability and easy crash recovery/less crashes? Put more in the DB.
> Do you want to be able to run 5000 players online at once? Methinks
> you'll need something more custom-built.
Funny story: In tinkering with exactly this, I've found it _is_ possible to
write cacheing systems that severely slow things down ;)
Seriously, most modern db systems are designed to deal with _lots_ of requests
per second - your average mud shouldn't stress your average db. However,
there's an added few milliseconds on every request which has to be dealt
with. In the end, cacheing is probably a good idea somewhere along the line,
depending on your design - if you're holding everything in db for persistance.
If you're just using the db as a load/save store area, then most of this
is irrelevant - you'll not stress the db, go for your life ;)
Incidentally, 5000 players online at once would suggest to me that a db is
a good idea - if for nothing else than for it's backup and replication
abilities.
> A fascinating thought I had a while ago was that, well, since the data
> structures by and large determine the way the game works, wouldn't it be
> neet to have spells that could actually alter the structure of the
> database? I mean, SQL commands can let you do things like add and drop
> tables, fields etc. Why limit the scope of the spells to simply altering
> values within the tables?
Because usually the table structure has no bearing on anything in-game?
My tables are in form:
CREATE TABLE attributes (
id int(11) DEFAULT '0' NOT NULL,
name varchar(32) DEFAULT '' NOT NULL,
last_update timestamp(14),
value text,
value_type varchar(20) DEFAULT 'string' NOT NULL,
value_exist char(1) DEFAULT 'Y' NOT NULL,
PRIMARY KEY (id,name)
);
(MySQL create statement). id is object id that owns this attribute,
name is name of attribute, value is value of attribute, value_type indicates
how to de-munge the value I've stored to get the right thing (text fields
in MySQL act close enough to blobs, so in essence I store a text representation
of any value, and know how to convert it back). last_update isn't actually
used atm. value_exist is part of my wierd inheritance scheme.
Modifying this structure would be fairly pointless ;)
There are some funky things you can do quickly in SQL, tho - give someone
a spell that tells them where the nearest x is, and finding the locations
of all the x's is at least considerably faster. (Then you've got to figure
out proximity, but that's another story ;). Global spells - something that
adds a temporary +1 to all swords in the world - are easier via SQL ;)
Oh, in inheritance world, changing all descendants of object x to be
descendants of object y is easier in SQL, too.
This stuff has been discussed before in the archives - worth doing a quick
browse through them. Search for 'MySQL' is probably the quickest and
easiest way to find info ;)
KevinL
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<LI><STRONG><A NAME="00474" HREF="msg00474.html">Re: [MUD-Dev] Database back ends</A></STRONG>
<UL><LI><EM>From:</EM> Greg Underwood <gunderwood@donet.com></LI></UL></LI>
<LI><STRONG><A NAME="00467" HREF="msg00467.html">[MUD-Dev] Database back ends</A></STRONG>
<UL><LI><EM>From:</EM> dwacks@saleslogix.com</LI></UL></LI>
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<ul><li>Thread context:
<BLOCKQUOTE><UL>
<LI><STRONG>[MUD-Dev] Massive Connections</STRONG>, <EM>(continued)</EM>
<ul compact>
<ul compact>
<LI><strong><A NAME="00481" HREF="msg00481.html">[MUD-Dev] Massive Connections</A></strong>,
Christopher Kohnert <a href="mailto:cjkohner@mail.uccs.edu">cjkohner@mail.uccs.edu</a>, Thu 20 Apr 2000, 01:34 GMT
<UL>
<LI><strong><A NAME="00483" HREF="msg00483.html">Re: [MUD-Dev] Massive Connections</A></strong>,
Kevin Scott London <a href="mailto:london@cs.utk.edu">london@cs.utk.edu</a>, Thu 20 Apr 2000, 02:52 GMT
<UL>
<LI><strong><A NAME="00484" HREF="msg00484.html">Re: [MUD-Dev] Massive Connections</A></strong>,
Christopher Kohnert <a href="mailto:cjkohner@mail.uccs.edu">cjkohner@mail.uccs.edu</a>, Thu 20 Apr 2000, 03:30 GMT
<UL>
<LI><strong><A NAME="00486" HREF="msg00486.html">[MUD-Dev] [Mud-Dev]: Sushi Mud</A></strong>,
Todd McKimmey <a href="mailto:rufus@wombatgames.com">rufus@wombatgames.com</a>, Thu 20 Apr 2000, 22:08 GMT
</LI>
</UL>
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</UL>
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</ul>
<LI><strong><A NAME="00478" HREF="msg00478.html">Re: [MUD-Dev] Database back ends</A></strong>,
Kevin Littlejohn <a href="mailto:darius@connect.com.au">darius@connect.com.au</a>, Wed 19 Apr 2000, 23:15 GMT
</LI>
</ul>
</LI>
<LI><strong><A NAME="00468" HREF="msg00468.html">[MUD-Dev] defeating twinking through game mechanics</A></strong>,
S. Patrick Gallaty <a href="mailto:choke@sirius.com">choke@sirius.com</a>, Wed 19 Apr 2000, 18:55 GMT
<UL>
<LI><strong><A NAME="00488" HREF="msg00488.html">Re: [MUD-Dev] defeating twinking through game mechanics</A></strong>,
Travis S. Casey <a href="mailto:efindel@io.com">efindel@io.com</a>, Thu 20 Apr 2000, 22:08 GMT
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</UL>
<UL>
<li><Possible follow-up(s)><br>
<LI><strong><A NAME="00480" HREF="msg00480.html">Re: [MUD-Dev] defeating twinking through game mechanics</A></strong>,
jolson <a href="mailto:jolson@micron.net">jolson@micron.net</a>, Thu 20 Apr 2000, 00:09 GMT
<UL>
<LI><strong><A NAME="00482" HREF="msg00482.html">Re: [MUD-Dev] defeating twinking through game mechanics</A></strong>,
adam <a href="mailto:adam@treyarch.com">adam@treyarch.com</a>, Thu 20 Apr 2000, 01:34 GMT
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