Global Temp Tables - SQL Server vs Oracle

Question

I am using Oracle 11g Global Temporary Tables as I need a solution where I can add rows to a temporary table for a join, and I want only the rows added to the temp table for

Answer 1

Temporary tables on SQL Server are local by default. The table will be dropped after the session ends. If you execute a script like:

create table #Foo (
       FooID  int
      ,FooCode1  varchar (20)
)

insert table #Foo (FooID, FooCode1)
values (1001, 'X')

insert table #Foo (FooID, FooCode1)
values (1002, 'Y')

select f.FooID
      ,f.FooCode1
      ,b.BarID
      ,b.BarCode1
  from #foo f
  join bar b
    on bar.FooID = f.FooID -- (or whatever predicate)

The query will only return rows that join on what you inserted into #Foo in this session. #Foo is local to the session; you can have multiple sessions with their own #Foo temporary table with no worries about namespace collisions. When the session is closed the temporary table will be discarded. You can also explicitly drop #Foo after you've finished with it if you're using a persistent database connection (e.g. a client-server desktop app).