Functions for manipulating the local schema cache object.
Interfact to modify the schema.
size: always means "bytes"
length: always means "elements"
example: the size of UInt64
 is 2*8 = 16, the length of UInt64
 is 2
All interfaces you get have an initial reference count of 1. To increment the count call 'AddRef'
and to decrement it call 'Release'. When the count reaches 0, the interface will be destroyed.
Every interface you don't need anymore should be released.