[Mierza]

Just wondering about storage modules. A coder left a question to me asking if we should use flat files, or maybe a database like MySQL or PostgreSQL.

Does anyone with experience here have any insight into the differences and pro's vs con's?

[Traithe]

[Kylotan]

I guess it depends on how much data you store, and how quickly you need access to it. Relational databases are not the ideal format for mud-style data queries so you often end up with most of your data cached in memory anyway. They would reduce the amount of time you have to spend on working out file formats and the like, but if your coder has to ask you which is better, then I'm sadly guessing that they don't know enough about normalisation of data to be able to reap all the benefits of the relational data model.

[xanes]

The database question comes up a lot.  I think you just can't put all your eggs or data in one basket.  Databases are fast, but RAM is faster.  

RAM is, also, often in short supply as requirements become arbitrarily large.  

As I see it, area data for a MASSIVE game might stand to benefit from a db, because unused (empty of PC) areas could be loaded and unloaded fairly painlessly.  

Another benefit I suppose, is that you could have a persistent connection to the DB for each player, and you could, with a little overhead, sync their player data with them pretty seamlessly.  That'd cut down on reimbursements, I suppose.

Also, the transferrability of data in a DB opens up the doors for all sorts of ideas that +might+ be worth looking at. A mySQL dataset would make a web-based building app not much of a headache....

In short, you just have to do what makes sense on a case by case basis.  Moderation in all things, yes?


-X

[Yui Unifex]

My own codebase, Aetas, uses a PostgreSQL backend. My codebase before that, Deus, used a MySQL backend. In my experience, using a relational database to store mud information is just so much more conveniant and flexible than not. If your mud just uses a dumb 'load everything on boot' model, and you only index by one value, then a relational database is probably not for you.

A relational database is immensely useful when using lazy loading. Our system only loads from disk an object that has been specifically requested, so it's very easy to do e.g. SELECT * FROM rooms WHERE elementid = X, or SELECT * FROM rooms WHERE name = 'Y'. Typical mud databases are poorly built for this kind of thing, because they tend to group collections of rooms / npcs / objects into area files that make seeking and updating specific items difficult. The database is also useful for searching within data for a match, such as when you want the builder equivalent of 'grep' to find bits and pieces of information.

As for accessing MUD data outside of the database, I may be getting off topic here but we use XML-RPC to query the MUD directly. This way we have no trouble keeping objects in sync. Fortunately implementing RPC methods is dead simple, as is making use of them in web builder apps

[Lanthum]

Does anyone know of any good sites with info or tutorials about how to use DBs?  I really want to use Dbs (either Access or MySQL) for certain aspects with my new codebase!  But I really don't know what I'm doing and I haven't been able to find any good sites with tutorials.  All it seems I can find is how-tos for .NET and VC++ specifically.

I know query structure and the like from an old class I took, but I have no idea how to connect to the Db from within my C++ program if it's not written for .NET or VC++.

Can anyone help?

[fredrik]

If you settle for MySQL, there's quite a lot of nice info on their own webpage, , including their C and C++ APIs.

[Lanthum]

[Yui Unifex]

. Of course you can use it in a UNIX non-.Net program. That is MySQL's principle audience.