Thread: ERROR: DefineIndex: index function must be marked iscachable

On Fri, 25 Jul 2003, Elielson Fontanezi wrote:

>     What can I do in this case?
>     I could not found anything about iscachable.


>
> postgres$ cat in.sql
> create index bt_proposta_f01 on proposta
> using btree (func_cod_secretaria(nr_proponente));
>
> postgres$ psql -d escola -f in.sql
> psql:in.sql:2: ERROR:  DefineIndex: index function must be marked iscachable

Check the create function reference page, I believe you'd need to add WITH
(iscachable) to the end of the function creation.

iscachable means that the function always returnes the same result when
given the same arguments.  It's a prereq to using the function in an
index. If your function doesn't meet those requirements (for example if it
does a query on a table) making an index on that function is a bad idea.

Dnia 2003-07-25 21:09, Użytkownik Elielson Fontanezi napisał:
> Hi all!
>  
>     What can I do in this case?
>     I could not found anything about iscachable.
>  
> postgres$ cat in.sql
> create index bt_proposta_f01 on proposta
> using btree (func_cod_secretaria(nr_proponente));
> 
> postgres$ psql -d escola -f in.sql
> psql:in.sql:2: ERROR:  DefineIndex: index function must be marked iscachable
> postgres$
You should follow the error. Your function func_cod_secretaria has to be 
declared as cacheable. (Look into documentation - sql commands / create 
function). IMMUTABLE function should help.

This function has also for some nr_proponente returns always the same 
value (look at IMMUTABLE description)

Regards,
Tomasz Myrta

On Fri, 25 Jul 2003, Stephan Szabo wrote:

> On Fri, 25 Jul 2003, Elielson Fontanezi wrote:
>
> >     What can I do in this case?
> >     I could not found anything about iscachable.
>
>
> >
> > postgres$ cat in.sql
> > create index bt_proposta_f01 on proposta
> > using btree (func_cod_secretaria(nr_proponente));
> >
> > postgres$ psql -d escola -f in.sql
> > psql:in.sql:2: ERROR:  DefineIndex: index function must be marked iscachable
>
> Check the create function reference page, I believe you'd need to add WITH
> (iscachable) to the end of the function creation.
>
> iscachable means that the function always returnes the same result when
> given the same arguments.  It's a prereq to using the function in an
> index. If your function doesn't meet those requirements (for example if it
> does a query on a table) making an index on that function is a bad idea.

Almost forgot.  In recent versions you'd specify that the function was
IMMUTABLE and I believe the error message would use such as well.  What
version are you using (it might be worth considering an upgrade to 7.4
when it comes out)