In the last episode (Oct 09), Ryan Shrout said:
> Well, here are some quick stats on the server when its running:
> Key Reads/Key Requests = 0.000936 (Cache hit = 99.999064%)
> Queries/second = 129.574 (/hour = 466465.492)
> Slow Queries/second = 0.000 (/hour = 0.000)
> Uptime = 2 hr 49 min 23 sec
> Are there any drawbacks to using InnoDB or DBD? If they are really
> better, why aren't they always used?
InnoDB requires you to pre-allocate a large tablespace file (like
Oracle), which it then uses to put indices and data in. It's also
index-organized based on primary key, so for certain operations it's
slower than MyISAM.
BDB tables are index-organized as well, and use page-based locks
(around 8K I think) instead of record locks like InnoDB.
The primary value of MyISAM tables are their speed when selecting from
them, since they don't support transactions and locking is so simple.
But, beware that table data is not cached, so every query must do a
physical read. If you mainly do lookups on the primary key, BDB or
InnoDB would probably be faster (they both cache index and data).
Most of the pros and cons for each table type are listed in the manual.