Re: performance/query tuning

In my experience, it does what you'd expect. It coerces the data type declared within you're program to that defined within the database.

If you populate your table with a large number of records, or alternatively enabling tracing, then you'll find out for sure.

If you're really worried you could always use the 'to_number' function !

Dietmar Leibecke wrote in message <34C5D377.3C267059_at_debis.com.--->...
>Hi,
>
>I'm selecting data from a table via the primary key (field: ID NUMBER(38)).
 In
>my Pro*C program I have a varchar host variable that keeps the id's value.
 What
>does Oracle do, when accessing the table the following way:
>
>#define ID_SIZE 38
>...
>varchar vc_id[ ID_SIZE + 1 ]
>...
>
>ORA_SETVC( vc_id, "5100" ); /* own macro that sets arr and len */
>
>EXEC SQL
> SELECT FIELD1, FIELD2 INTO :vc_field1, :vc_field2 FROM SOMETABLE WHERE
>ID=:vc_id;
>
>Does Oracle convert the host var field into number type (what I hope is the
 way
>it works) or convert the SOMETABLE.ID field into varchar and perform a full
>table scan by disabling an index this way (very bad) ???
>
>Thanks for any input,
>
>--
>Dietmar Leibecke
>----------------
>Address is altered to discourage junk mail.
>Remove ".---" for the real address.
>
>
Received on Wed Jan 21 1998 - 00:00:00 CST