Re: best way to "parameterize" a tablename?

On Aug 22, 1:13 am, m..._at_pixar.com wrote:
> gym dot scuba dot kennedy at gmail <kenned..._at_verizon.net> wrote:
>
> > <m..._at_pixar.com> wrote in message
>
> > >    if tablename = 'FOO'
> > >        insert into foo ...
> > >    else if tablename = 'BAR'
> > >        insert into bar ... (exact same stuff)
> > >    etc...
>
> > Use bind
> > variables.)
>
> I guess that's what I'm asking... how can I use bind variables or
> equivalent for the table name?
>
> > You have an odd schema is each table has the same structure but a different
> > name.
>
> There's a reason for it, we basically don't want to intermingle
> one set of data with another.  Think of the case where there's
> a million records of FOO and 100 records of BAR.  An index
> won't be very useful, so you end up doing a lot of full
> table scans to extract the data, and we don't want to pay
> the big cost of FOO for the tiny data from BAR.  The real
> case is a bit more complicated, but that's what it boils
> down to.
>
> Thanks!
>
> --
> Mark Harrison
> Pixar Animation Studios

You could give multitable insert a shot:

SQL> var tablename varchar2(30)
SQL> var somevalue varchar2(20)
SQL> exec :tablename := 'wr_t1'; :somevalue := 'Banana'

PL/SQL procedure successfully completed.

SQL> insert first

  2      when :tablename = 'wr_t1' then into wr_t1 values (:somevalue)
  3      when :tablename = 'wr_t2' then into wr_t2 values (:somevalue)

1 row created.

SQL> select * from wr_t1;

COL

1 row selected.

SQL> select * from wr_t2;

no rows selected

Alternatively partitioning would probably handle this type of thing. Received on Fri Aug 22 2008 - 04:20:33 CDT