INN and db 4,6

[Marc Stürmer]

Am Montag 24 September 2007 schrieb Bill Davidsen:

> What do you see as the "fast enough?" I don't have MySQL numbers I
> trust, but Postgress is available as well.

You've got to take a look at the engines. 

MySQL has two big engines - MyISAM and InnoDB (now owned by Oracle as BDB, by 
the way).

MyISAM is the fast engine of MySQL, but it's not ACID-safe, that's why it is 
so fast. It's usable for data that's not sooo important, so this leaves 
overview OUT. 

InnoDB is the ACID-safe engine from MySQL. Since it's that, it needs more 
horsepower, but is safer and would be the thingie of choice for an overview 
database, since it's supposed to be in a cleaner state after a crash.

MyISAM instead could need runs from myisamchk. 

Postgres has only one engine. It's doing something called MVCC. This is also 
ACID-safe and enabled by default, you got no choice there. 

Since all of the requests to an external DB need to run first through the OS 
and then through the engine and back it's of course faster to just skip all 
of this overhead and embed an engine instead. An external DB would also need 
added maintenance sometimes and when it hangs, well... ok, BDB is also 
externally implemented, but is still a more lightweight solution than 
MySQL/Postgres. 

By the way, many consider still MySQL to be faster than Postgres under normal 
load and Postgres handling many concurrent requests better than MySQL (e.g. 
take a look at this benchmark: http://tweakers.net/reviews/657/6). 

So the best bet if possible and wanted would be to use an embeddable SQL 
engine like SQLite.