Creating index on subtype-specific attribute in a SQL Object table
sql,oracle,indexing,object-type,subtyping
create index i_stock_number on documents d (treat(value(d) as publication).stock_number); Assuming a data model like this: create or replace type document is object ( id number, title varchar2(100), file_size number ) not final; create or replace type publication under document ( stock_number number ); create table documents of document; insert into...
if the type of instances is simply 'instance', how does Python know these are instances of the foo class? [closed]
type() does not work correctly for instances of old-style classes (Python 2 classes that do not inherit from object). Python looks at the .__class__ attribute instead: >>> class Foo: ... def __init__(self): ... self.name = 'frank' ... self.id = 7 ... >>> f = Foo() >>> type(f) <type 'instance'> >>>...
Oracle PL/SQL table of parent object type breaks when I add another inheriting child object type
Instead of FORCE you should use the VALIDATE option when dropping types: VALIDATE If you specify VALIDATE when dropping a type, then Oracle Database checks for stored instances of this type within substitutable columns of any of its supertypes. If no such instances are found, then the database completes the...
Dynamically choose object type
What you have is quite close to working, and I think you merely have a misunderstanding. But this requires associate_name in select type construct. Associate_name should be a pointer to initial_conditions_geometry, but one cannot set target attribute to derived type field. An associate-name is required in this case but, regardless...