Q:

Column locking in innodb?

I know this sounds weird, but apparently one of my columns is locked.
select * from table where type_id = 1 and updated_at < '2010-03-14' limit 1;

select * from table where type_id = 3 and updated_at < '2010-03-14' limit 10;

The first one would not finish running even in a few hours, while the second one completes smoothly. the only difference is the type_id between the 2 queries. 
A bit of background, the first statement screwed up before which I had to kill manually.

A:

It seems like you do not have an index on (type_id, updated_at) and your table is rather large.
Creating the index should fix the problem:
CREATE INDEX type_updated_idx ON table (type_id, updated_at);

Assuming, you have enough permissions to make data definition statements.

