[vworld-tech] Database usage

[Lee Faris]

Brian Hook wrote:

> - how do others use the database?

We have a cache layer over the DB.  Almost nothing is put in the cache at
load time.  As players log in and access rooms all the associated data is
read in to the cache.  It keeps a list of the most recently used objects.
When new objects are added and the list is full the cache will dump the
objects at the bottom of the list.  The size of the list is tweakable so you
could set it to be nearly disk-based to have room for the whole db in
memory.

> Do people actually query the DB at run-time or do they try to
> only do it at load time?

Answers of course depend on the desired scalability and level of
persistance, but asking around about the possibility of not using a cache I
got mixed answers.  It seemed (to be stereotypical) that people who write
business applications that use DB's are convinced a MUD could query the DB
for everything it needs.  They would mention websites supporting X many
concurrent users and how a certain DB has done Y queries/minute.  But it
seems to me that a MUD would use the data in a very different way than the
website.  Much more write intensive.  And could the DB/disk handle that high
load of queries for potentially 24 hours a day?  I think at the very least
it would be a scalability factor.  And I would rather not have to worry
about how many read/writes each function is going to cause because I'm
worried about the database load.

Lee