Commented by: Sean Leyne (seanleyne)

This is as designed, if you include the RDB$Format column in your select, you will see that each entry has a different value, to represent the different versions of the VIEW/Table which may be in use by connections.

Commented by: @asfernandes

> This is as designed, if you include the RDB$Format column in your select, you will see that each entry has a different value, to represent the different versions of the VIEW/Table which may be in use by connections.
>
I don't think so. Looks like a problem of the new ALTER VIEW. AFAIR, RDB$VIEW_RELATIONS is not used for something very important, so nobody noticed problem. But I'll investigate it.

Commented by: Alex Bekhtin (afgm)

> This is as designed, if you include the RDB$Format column in your select, you will see that each entry has a different value, to represent the different versions of the VIEW/Table which may be in use by connections.
but You can not delete tables table_1 and table_2, because FB sees dependencies.

Commented by: Claudio Valderrama C. (robocop)

This is a bug.
A recreated object must not keep obsolete references. If I use the proposed db, I can do:
SQL> set term ^;
SQL> set list^
SQL> select * from rdb$dependencies^

RDB$DEPENDENT_NAME VW_TABLE
RDB$DEPENDED_ON_NAME TABLE_3
RDB$FIELD_NAME <null>
RDB$DEPENDENT_TYPE 1
RDB$DEPENDED_ON_TYPE 0

RDB$DEPENDENT_NAME VW_TABLE
RDB$DEPENDED_ON_NAME TABLE_3
RDB$FIELD_NAME ID
RDB$DEPENDENT_TYPE 1
RDB$DEPENDED_ON_TYPE 0

As you see, the only dependencies are due to the last definition. Previous definitions can hold the old format, but the new view doesn't have to be tied to objects it doesn't access. After all, if you try to drop the view, you're dropping the current version on disk.

Imagine the same sequence with procedures:

SQL> create procedure p1 as begin end^
SQL> create procedure p21 as begin end^
SQL> create procedure p2 as begin end^
SQL> create procedure p3 as begin end^
SQL> create or alter procedure p as begin execute procedure p1; end^
SQL> create or alter procedure p as begin execute procedure p21; end^
SQL> create or alter procedure p as begin execute procedure p2; end^
SQL> create or alter procedure p as begin execute procedure p3; end^
SQL> commit^
SQL> select * from rdb$dependencies^

RDB$DEPENDENT_NAME P
RDB$DEPENDED_ON_NAME P3
RDB$FIELD_NAME <null>
RDB$DEPENDENT_TYPE 5
RDB$DEPENDED_ON_TYPE 5

At this time, I should be able to drop p1, p21 and p2 and I indeed can do that.

Commented by: @pcisar

QA test added.