[DOCS] Shadowdb and Table locking issues

[Sam Folk-Williams]

I am updating the docs on the configuration parameters
(http://www.bugzilla.org/docs/tip/html/parameters.html), and I have a
question on the shadowdb bits. It looks like the described behavior of
MySQL and table locking is still accurate as of MySQL 5. But, I'm
wondering if this same issue exists in Postgres and Oracle? I'd like
to add a reference to the other DBs for completeness.

Also, I'm wondering if this bit should still be included or if anyone
can provide an update on this:

"Note that more recent versions of mysql support row level locking
using different table types. These types are slower than the standard
type, and Bugzilla does not yet take advantage of features such as
transactions which would justify this speed decrease. The Bugzilla
team are, however, happy to hear about any experiences with row level
locking and Bugzilla."

Is it still the case that we don't take advantage of these features?
Are there new recommendations for dealing with this? For example,
MySQL docs say to use InnoDB or BDB to get around the locking
problem...

Thanks,
Sam