Hi,
When designing some library tools using dbi/dbd to update a table in an
Oracle db, we are facing the following scenario:
Let's say there is a table created as:
SQL> create table test1 (c1 varchar2(10) primary key, c2 varchar2(10), c3
varchar2(10));
SQL> create index test1_ix1 on test1(c2);
SQL> insert into test1 values ('a', 'b', 'c');
SQL> commit;
Now compare the following two update statements:
statement1: update test1 set c3 = 'd' where c1 = 'a';
statement2: update test1 set c2 = 'b', c3 = 'd' where c1 = 'a';
They both result in the same final result, but does statement2 involves some
extra work on the index created on c2 so statement1 is more efficient? From
the programmers point of view, it is easier to write some generic update
statements without know exactly which column is being actually updated.
Thanks.
> Dong Wang
> Grand Central Networks
> [EMAIL PROTECTED]
>
