according to the documentation of cacheGetAll() - "this function return a structure containing all elements inside the cache." The documentation further states that both filter and region are optional. However, if a region is not specified only the items within the default region are returned.

Intuitively this method should return a structure of structures in the form of [region][key][value]

test case:

<cfscript>
cachePut(id='abc',value='123');
cachePut(id='def',value='123');
CacheRegionNew("foo");
cachePut(id='foo-abc',value='123',region="foo");
cachePut(id='foo-def',value='123',region="foo");
writeDump(cachegetall()); //returns only from default
writeDump(cachegetall(region='foo'));
</cfscript>