Semi-OT, BIND dlz and excessive queries

[Scott Haneda]

The DLZ users mailing list is pretty quiet, thought to ask here in  
case someone can elaborate.

I have MySql query logging on so I can see the queries as they come in  
for testing.

dig example.com @localhost
This yields a hit to the database of
090509  5:50:56	   2593 Query       SELECT zone FROM resource_records  
WHERE zone = 'example.com'
		   2593 Query       SELECT zone FROM resource_records WHERE zone =  
'com'

Two hits.

dig a.b.c.d.f.g.h.i.j.k.l.m.n.o.p.q.r.s.t.u.v.w.x.y.z.example.com  
@localhost A
Small snip of the log for that one, I am sure you get the idea:
2593 Query       SELECT zone FROM resource_records WHERE zone =  
's.t.u.v.w.x.y.z.example.com'
2593 Query       SELECT zone FROM resource_records WHERE zone =  
't.u.v.w.x.y.z.example.com'
2593 Query       SELECT zone FROM resource_records WHERE zone =  
'u.v.w.x.y.z.example.com'
2593 Query       SELECT zone FROM resource_records WHERE zone =  
'v.w.x.y.z.example.com'
2593 Query       SELECT zone FROM resource_records WHERE zone =  
'w.x.y.z.example.com'
2593 Query       SELECT zone FROM resource_records WHERE zone =  
'x.y.z.example.com'
2593 Query       SELECT zone FROM resource_records WHERE zone =  
'y.z.example.com'
2593 Query       SELECT zone FROM resource_records WHERE zone =  
'z.example.com'
2593 Query       SELECT zone FROM resource_records WHERE zone =  
'example.com'
2593 Query       SELECT zone FROM resource_records WHERE zone = 'com'

Is this expected behavior?   This seems quite a simple way to  
potentially bring a data source to it's knees.
-- 
Scott * If you contact me off list replace talklists@ with scott@ *