Cached variable remains after truncating cache table I updated a row in the variables table to change the value of a variable. Then I truncated the cache table. But a call to variable_get() still returns the original value. 

I thought that the variables were cached in the cache table, so where could this original value be hiding?

EDIT: I waited a few minutes and tried again and it was OK. So the immediate problem is solved, but I would like to understand what happened. Is there another layer of caching? It seems there must be since it could not have gotten that value by querying either cache (empty) or variable (containing new value).
Got it - the call to variable_get() was during the bootstrap process, so cache_bootstrap table also needed to be truncated.